373
1 INTRODUCTION
Regardless of their size or purpose, seaports, as part
of global transportation system, have the character of
traffic complexity, especially in their maritime
domain. Tendency of port officials to attract and
produce a higher shipping activity can sometimes
cause a traffic overcapacity of infrastructurally limited
port areas. If the diverse traffic mix and external
influences such as wind or sea are also taken into
account, then the possibility for degradation of ports
safety and environmental standards is quite likely. In
order to control the maritime activity’s and address
mentioned challenges, some seaports are investing
their resources in development and application of
new methods and technologies.
In recent years, there is an increasing number of
researches where risk appraisals were conducted with
an aim of providing safe navigation and level of
ecological sustainability of port areas. Manny of them
based their input on historical data, but also on an
information gathered by Automatic Identification
System (AIS), device that is essentially used for
marine traffic surveillance. Because of its ability for
displaying up-to-date vessel position tracking, speed,
ship particulars, etc. AIS is very convenient source of
input info for traffic control operations. In research
conducted by S. L. Kao et al. both historic databases
and AIS data were used for calculating safe vessel
manoeuvring speeds that should mitigate
navigational and air pollution danger in Keelung Port
[4]. X. B. Olba et al. also included AIS data in their
paper with a goal of enhancing navigational safety
through risk assessment model and defining risk
index that could be applicable on various ports [3].
AIS-sourced info about ships and their movement
progression were examined and applied in scientific
Design and Application of an Automated Smart Buoy in
Increasing Navigation Safety and Environmental
Standards in Ports
F. Bojić
1
, I. Karin
2
, I. Juričević
2
& M. Čipčić
3
1
Maritime University in Split, Split, Croatia
2
Plovput d.o.o., Split, Croatia
3
Oculi mare d.o.o., Split, Croatia
ABSTRACT: The growing demand for transportation has brought even larger quantities of traffic in spatially
limited port areas. Considering a diverse traffic mix, infrastructural overcapacity and busy schedule, port
communities have started to face possible degradation of safety and environmental standards. To mitigate these
problems, a number of different monitoring solutions of marine environment were deployed. Since
conventional environmental and traffic data gathering by physical monitoring and sampling was logistically
complicated and inefficient in time and resources, different approaches had to be considered. With the rise of
accessible Internet of Things (IoT) technology some ports already installed smart monitoring devices such as
smart buoys. The goal of this paper is to examine the concept and benefits of an automated smart buoy as a cost
effective, easy to install device capable of real-time remote information sharing. Furthermore, the design and
operational processes of existing automated smart buoy will be presented, along with solutions for tackling
navigational safety and environmental problems.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 15
Number 2
June 2021
DOI: 10.12716/1001.15.02.14
374
studies for Shanghai Yangshan port done by S. Song
and Las Palmas Port carried out by M. Tichavska and
B. Tovar, that aimed to secure more precise prediction
of air pollution [8, 9]. Dynamic ship information such
as speed and time spent in a particular activity proved
to be significantly important for obtaining relevant
results in both air quality studies, and this data would
be very difficult to accurately determine without the
AIS transponder.
Although AIS offers detailed and in near-real time
insight about static and dynamic marine traffic data,
content that it displays includes only vessels that are
required to have transponder installed on board [14].
Because of limitation which excludes small scale ships
that sometimes make up a significant share of traffic,
especially in the wider port areas, new ship-
movement monitoring solutions are more often
deployed.
Development of Internet of Things (IoT)
technology offered opportunity for integration and
communication between various devices and users.
Generally, IoT web can be described as a three-layered
system [7]. First one is physical unit, typically a type
of sensor that collects data from environment. Second
component is responsible for wireless distribution of
data to central computing unit where collected info
are stored and processed. Lastly, application layer on
its interface visualizes processed data and can
sometimes offer operational options or solutions to
the user [15]. Because of its adaptability IoT-based
system are more frequently being applied in different
port segments. In terms of navigational safety and
environmental control inside port areas, maybe the
best example of IoT application is novel smart buoy
concept.
As a system integrated in IoT network, smart buoy
is technological solution that has function of a sensor,
designated for data collection in the marine
environment. Depending on the design and
specialized purpose, it can be able to monitor traffic
and hydrometeorological conditions, sample the
water and communicate with its surroundings.
This paper is arranged in five different sections
that explore the design and role of smart buoys in
traffic and environment monitoring. Section 2.,
divided in two Subsections, elaborates general
concept of smart buoy system, their design and
technologies used for development. Section 3
examines various application of smart buoy devices.
Two Subsection of Section 4. provide detailed insight
in design and application of the Marine Eye, first
smart buoy concept deployed in region. Finally, in
Section 5. Conclusion and observation of current and
future smart buoy concept benefits are provided.
2 SMART BUOY DESIGN
To reduce navigational danger and the negative
impact of the maritime transport industry on the
environment, port communities are continuously
developing ways to monitor maritime traffic with a
goal of collecting relevant data that can be used as an
input values in different models of risk assessments. It
is essential to gather information on large enough
spatial and time scales to assure effective monitoring
of port environment and to be able to produce
solutions to reduce the negative impact of human
activity on these ecosystems [2]. In order to achieve
that, a number of ports rely on AIS transponder for
marine traffic monitoring, but most recently, this
tracking method is supplemented with new smart
buoy device. As a part of IoT system, buoy-based
coastal monitoring systems are suitable for surveying
and controlling the status of waters, as installation
and maintenance are simple to perform and not very
costly [2]. Also, they can have the technical means that
enable sampling and variable adjustment of sampling
frequency [1].
2.1 General configuration, components and main features
of smart buoy concept
Like many other smart systems based on the IoT
technology, general concept of smart buoy devices can
be defined as a three-layer structure. Sensor layer is
responsible for gathering data from physical
environment and its transformation into digital form.
This type of sampling is performed by various types
of specialized sensors for traffic or environmental
survey. Primary function of connection and data
preparation layer is to transfer gathered information
from the sensor layer, using different wireless
communication technologies, in order to be received,
stored and processed by central computing system.
The goal of this process is to secure wireless and
automatised data transmission without any
deficiencies and to prepare collected info for next
phase. Also, different communication networks can be
used, depending on the needed of coverage area.
Application layer provides interface that contains the
possibility of viewing the collected data and
sometimes tools for remote management of operations
and processes. Commonly, specialised software is
compatible with different operating systems and can
be accessed through smart devices. General smart
buoy composition concept is illustrated in Figure 1.
Figure 1. General three-layered concept of smart buoy
devices
Although, the conceptual arrangement of smart
buoys can be universally described as three-layered
structure, it’s the design depends on specific
375
operational purposes. So, to apply buoy-based
monitoring system in port areas with a goal of
collecting traffic and environment data, it should have
next features:
− Wireless communication – collected data exchange
via Bluetooth, ZigBee, Wi-Fi, etc. for low-range
transmission or WiMAX, GSM, GPRS for long-
range transmission [11]
− Energy consumption – achieving power efficiency
by autonomous activation of sampling processes
and power management system
− Autonomy – possibility of continuous and real-
time environment and traffic tracking
− Remote access – remote management of operations
and processes (sampling when required, external
communication, repairing if system error occurs,
etc.) for end-user via application interface
− Energy harvesting – enabled to derive energy from
external sources. Equipment type should
correspond to characteristics of available ambient
energy sources.
− Cost effectiveness - system design that assures
efficient resource utilization to reduce the costs of
manufacture, deployment, operation and
maintenance [2]
− Simple deployment – easy to install without
requiring any onsite configuration and specialist
equipment and can ideally be done by a single
person. Also, simple transferability of the device
should be enabled [10]
− Redundancy – if system encounters break-down of
connection or low battery power it should be
complemented with the extra components to
ensure no data loss and continuous sampling until
repaired
− Integrity – device case has to be water tight and
highly resistant against complex marine
environment. Corrosion and biofouling protection
is also required. Automatized cleaning of sampling
and monitoring systems should need to be
installed to avoid frequent maintenance
interventions. Also, strong stability against adverse
atmospheric conditions needs to be obtained [2, 11]
− Maintenance - the design of the buoys should
facilitate access to their components for
maintenance and eventual dismantling. On top of
that, system support for remote access has to be
enabled [2]
− Modularity – the device should be designed in a
way that enables additional modifications for
improvement of its current components and
adaption to the new technologies. System should
be flexible and customizable enough to
accommodate heterogeneous devices and
communication technologies[2, 10]
Although, general concept of smart buoy system
displayed in Figure 1. should incorporate all features
that define individual device, the technology and
equipment implemented for completing main
operations can vary.
2.2 Common physical, communication and central
computing technology
The right choice of marine environment monitoring
sensors depends on the user requirements of
deployment area, measurement range, accuracy,
resolution, power consumption, and intended
deployment time [11]. For monitoring port related
traffic activities and sounding environment, camera
system should be integrated inside waterproof case.
To ensure accurate meteorological conditions that
could negatively affect navigational safety, physical
parameters, such as temperature, humidity, pressure,
wind speed and wind direction should also be
continuously monitored [11].
For data transferring from physical smart buoy
component to control centre that is responsible for its
processing, system must use at least one of various
wireless communication technologies (WCT).
Wireless communication has different standards,
frequencies and transmitting distances, so there are
several options for data transferring. For example, Wi-
Fi, ZigBee, Bluetooth, LTE, etc. are often used for
smaller distance, while WiMax, GSM or GPRS are
used for long range communication [11]. Wi-Fi is a
wireless network of exceptional similarity to a wired
one, with the difference that data transmission cables
are not required in this way [5]. It operates at a
frequency of 5.8 GHz and speed of 7Gbps. ZigBee is
low power consumption device. It operates at 868
MHz and data is sent using a packet of size of max.
1024 bits. Also, it is possible to establish network with
more than 60,000 devices connected to network.
Figure 2. shows ZibBee network.
Figure 2. ZigBee network topology [5]
Bluetooth is a low power technology. It is suitable
to transfer data between two or more devices. There
are two types of this technology – Basic
rate/Ehchanged and Bluetooth Low Energy
(BluetoothLE). The LTE (Long Term Evolution) is
based on IP protocol. It supports IPv4 and IPv6
standard [5]. The speed of data transfer with this
technology can be higher than 1 Gbps. WiMax enables
stable data transfer speeds of up to 40 Mbps, and in
the experimental phase the speed is up to 1 Gbps [5].
Also, WiMax can cover more are then previously
mentioned WCTs but more importantly it can help
service providers to meet many of the challenges they
face due to increasing operational demands without
discarding their existing infrastructure. This is
possible because of its ability to seamlessly
interoperate across various network types [19]. GSM
is standard system for communication via mobile
telephones incorporating digital technology. In
addition to the fact that it covers wide areas, GSM
offers low-cost, high-quality and compatible
communication net [11, 13]. Since, GPRS is based on
GSM standards it offers similar futures but on the 2G
and 3G standards that enable faster and constant
communication.
Table 1. shows a comparative overview available
data transfer solution. According to the presented
376
data, but also some technical details presented
previously, it is evident that none of the available
technologies is solution without shortcomings. This is
due to short range, insufficient number of base
stations, low data transfer speed or high-power
consumption [5]. Based on this, it is possible to
encompass two technologies, which synergistically
provide the possibility of networking and monitoring
many types of buoys on different micro locations.
Table 1. Comparison of available data transfer solutions [5,
11]
_______________________________________________
Technology Frequency Range (max.) Speed
_______________________________________________
Wi-Fi 2.4 GHz, 100 m 1-54 Mb/s
3.6 GHz,
4.9 GHz,
5 GHz,
5.9 GHz
WiMAX 3.5 GHz 50 km 75 Mb/s
LTE/LTE-A 2.5 GHz, 30 km 300 Mb/s (DL)
5 GHz, 75 Mb/s (UL)/
10 GHz, 1 Gb/s (DL)
15 GHz, 500 Mb/s (UL)
20 GHz
Bluetooth 2.4 GHz 100 m 1 Mb/s
ZigBee 2.4 GHz 20 km 250 kb/s
WiMAX 2–11 GHz <10 km <75 Mb/s
GSM 850/900/1800/
1900 MHz Dependent on 9.6 Kb/s
service provider
GPRS 850/900/1800/ Dependent on 56–144 Kb/s
1900 MHz service provider
_______________________________________________
Using any of the above communication solutions,
for the proper operation of smart buoys it is crucial to
establish a complete system, whose primary function
is to collect and display data or signals that are
sampled on individual buoys.
As it is illustrated in Figure 1. complete smart buoy
system should incorporate physical equipment of
buoys (PLC - Programmable Logical Controller,
sensors, etc.), communication infrastructure that
operates through different WCT and control centre. If
there are several control centres, they are connected to
a VPN (Virtual Private Network) network based on
TCP / IP technology, while the buoys are connected to
the centre using one of the mentioned WCT
technologies previously mentioned.
Data collected from smart buoys are stored in
databases and depends on type of equipment installed
and the primary purpose of each buoy, such as:
− Video surveillance of maritime traffic
− Measuring the density of maritime traffic at a
particular location
− Vessel identification
− Seawater sampling
− Pollution control
Control centre of smart buoy systems is equipped
with a specialized computer application such as
SCADA (Supervisory control and data acquisition),
web-based SCADA or similar applications developed
specifically for this purpose. Modern SCADA systems
enable the display of buoy data at more different
locations and on a few types of platforms, as shown in
Figure 3.
Figure 3. SCADA computer application [6]
As mentioned before, described physical,
communication and central computing component are
key elements for development of a smart buoy system,
but the diversity of monitoring applications makes
differences between smart buoy designs.
3 GOOD PRACTICES OF DIFFERENT SMART
BUOY APPLICATIONS
Wireless sensor networks are a highly promising
technique for monitoring marine environments
because of their advantages of easy deployment, real-
time monitoring, automatic operation, and low cost
[11]. So, this chapter explores and describes good
examples of some smart buoys in the world,
regardless of the basic application of each of them.
The following is an example of meteorological
add-ons installed in Sidney - Australia, listed by
AXYS. The buoy was installed at the micro-location of
the port of Port Aux Basques at a depth of about 50
meters. Its main purpose is to monitor meteorological
and oceanographic data in order to support
operational efficiency, safety and other segments
important for maritime transport [18]. The same data
are transmitted in real time, equipped with devices
that have the ability to measure different atmospheric
and surface conditions such as wind speed and
direction, humidity, temperature, dew point, pressure
and more. In addition to the above, the buoy is also
equipped with navigation information systems such
as AIS, which gives it the ability to directly transfer
data to ship bridges. Figure 4. shows meteorological
buoy.
Figure 4. Meteorological buoy
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MariaBox buoys that have been installed in Cyprus
- Spain, are used for the purpose of wireless analysis
of the marine environment for the control of chemical
and biological pollutants [12]. Some of the more
significant features of the device are high sensitivity,
the ability to repeat measurements over a long period
of time and the ability to stand permanently at sea.
Also in the final stage of development is the upgrade
of the buoy with bio sensors for chemicals created by
human influence and micro algae toxins relevant to
shellfish, fish and the marine environment. The
system will be implemented at micro locations in
Cyprus, Ireland, Spain and Norway at depths of 30 m.
The MariaBox buoy is shown in Figure 5.
Figure 5. MariaBOX buoy
Traffic and environment monitoring smart buoy
system shown in Figure 6. was deployed in Stockholm
Norvik Port.
Figure 6. Smart buoy in Stockholm port
The buoy is an energy efficient navigation beacon
with technology for position monitoring and remote
adjustment of the buoy's light intensity, which
changes depending on the weather [17]. The buoy is
0.8 meters in diameter and is about 10 meters high, of
what 3.5 meters can be seen above sea level. It is
equipped with LED lights and batteries with a
capacity sufficient for five years of continuous
operation. A 25-meter-long anchor line, connected to a
14-ton concrete block, secures the buoy on a sloping
seabed. It is made of polyethylene plastic, which is an
excellent choice of material for buoys because
maintenance is not required and the longevity of the
material in the sea is guaranteed. The plastic is
resistant to various ice and weather conditions, retains
colour and does not wear out due to seasonal
variations or UV radiation. The slippery surface is less
prone to marine fouling, and the buoy does not need
to be lifted for maintenance such as sandblasting and
painting, as is the case with steel buoys that need
overhaul at least every two years.
The plastic buoy is lighter than a similar steel
buoy, so it can be installed and maintained by smaller
ships and lifting equipment. As the inclinations of the
buoy are smaller than the inclinations of a similar
steel buoy, the required weights and anchor chains
may be smaller. In addition, the chain consumes less,
which will save hundreds of meters of chain over the
life of the buoy. It is equipped with a remote control
and monitoring system so that maintenance can be
planned based on accurate real-time data transmitted
from the buoy.
Information such as battery power level, exact
buoy position and other possible monitored functions
are available via a web browser. The said surveillance
system is equipped with a battery with a capacity
sufficient for continuous operation for five years, and
the manufacturer is working on the development of
attack systems related to alternative energy sources.
4 MARINE EYE - NEW NAVIGATIONAL SAFETY
AND ENVIRONMENTAL MONITORING SMART
SOLUTION
Supervision and management of maritime domain has
exceptional strategic interest for all maritime
countries, including the Republic of Croatia, mainly
due to the fact that maritime domain is one third of
Croatian territory. The lack of high-tech solutions on
the market that can improve safety on the maritime
domain was the motivation to construct and deploy a
new smart buoy system called Marine Eye. This
system is designed as a combination of computer
vision and artificial intelligence technology with the
hardware solution [16]. The project initiator is a local
company from Split. Technical and logistical support
for the project is provided by two other companies
based in Split, one specialized in the design and
manufacture of electronic devices, and the other
specialized in the maintenance of maritime domain.
The project was recognized as innovative by city and
county public organizations as well as a state agency
specializing in investments in innovative projects.
Through their public tenders for co-financing
innovative projects Marine Eye project received funds
that helped developing a prototype. Professional
support for the project was provided by the Project
Office of the University of Split [16].
4.1 Systems design
The Marine Eye system is intended for continuous
monitoring of the number of vessels on a certain part
of the sea in real time. The system, presented in Figure
7., consists of two parts: 1) a central software system
for data processing and 2) an electronic device
equipped with a specialized system for collecting and
sending data. The electronic device operates
autonomously because it has its own power supply
consisting of a solar panel and an associated battery.
The electronic device also has the software for
automated periodic production of photos at an angle
of 360° and sending these photos to a central
378
computer system. The electronic device is designed so
it can be easily set on a custom buoy which is then
placed on the certain part of the sea surface to be
monitored.
Figure 7. Electronic device - Marine Eye, 3D model
The development of the electronic device began
with the development of the so-called pre-prototype
of limited possibilities. That is actually a common
action in the process of developing more complex
electronic devices during which unforeseen
circumstances often occur, but also errors that are then
corrected when making a prototype It happens very
often that components ordered from suppliers online
do not correspond to the characteristics listed in the
available documentation and catalogues. Therefore, it
is necessary to perform your own testing of
components to make sure of their functionality. The
pre-prototype phase revealed errors in the initially
ordered cameras that were supposed to generate 360°
photos. Therefore, new cameras were ordered that
proved to be functional and a total of seven cameras
were installed in order to generate 360° high quality
photos. In addition to making the electronic device
needed to take photos, it was necessary to design an
adequate waterproof case that would then be simply
applied to the buoy. The case consists of a base in
which the battery and antenna were located, as well as
a cover for powering and charging the battery. A
transparent wall cover was attached to the base of the
case, in which the device for taking photographs was
placed [16].
Solar power supply, enabled by panels placed on
the buoy, with wireless data transmission allows full
autonomy of the system. Data collected from an
electronic device, which is mounted on a buoy, is
stored and processed in a central computer system.
The central computer system through a specially
adapted interface offers the possibility of viewing the
collected data on the daily basis of which certain
trends can be monitored, and also certain statistics can
be made. The development of the software system
was divided into three parts:
− a vessel recognition algorithm
− a system for receiving and processing data
collected from the electronic device attached on the
buoy
− an application interface for reviewing the collected
and processed data
Marine Eye system is constructed in a way that
secures resistance from various movements caused by
wind and waves. The system works by sending high-
resolution photos taken by a seven-camera system on
an electronic device attached on a buoy to a central
computer system using GSM technology. By
processing photographs obtained from an electronic
device attached on a buoy, vessels are detected using
computer vision technology. The application for
potential users of the Marine Eye system is available
on personal computers, tablets and smartphones [16].
4.2 Systems application
As part of the research and development process, with
the technical and logistical support of a local
specialized company for the maintenance of maritime
domain, a prototype of the Marine Eye System was
installed in July 2020 in the port in front of the city of
Trogir. An electronic device is applied to the existing
buoy. Certain modifications have been made to the
case of the electronic device, the solar panel as well as
the buoy itself can fit well together and in order to
make the system functional [16]. Installation process
and its final position are illustrated in Figure 8. and
Figure 9.
Figure 8. Installation of an electronic device of the Marine
eye system on a buoy in the port of Trogir
Figure 9. Marine eye device and solar panels attached on a
buoy in the port of Trogir
379
After several months of testing the prototype, it
was concluded that over the certain period sufficient
quality photos are generated from an electronic device
attached on a buoy despite the negative
environmental influences, such as sea waves. It was
concluded that the whole process can be successfully
repeated. It was also concluded that the central
software system based on the delivered photos
recognizes the vessel with high quality. Prototype
testing has shown that the Marine eye system is
perspective solution for monitoring the sea surface.
Since testing phase had shown that Marine Eye can
be a reliable source for traffic data gathering through
systems integrated autonomous cameras, now focus is
on quantification and analysis of collected info. Data
captured by systems cameras is processed by a vessel
recognition algorithm, and after software showed
adequate precision of its recognition ability, the info
that is still being collected should in the end represent
relevant data set of port traffic and its dynamic. Valid,
real-time and complete information about marine
traffic with its quantification and segregation makes
basis for future development of precise gas emission
inventory and navigational safety assessments. That is
especially important for smaller ships that do not
have AIS transponder installed on board. This
category of ships has quite vague contribution in
navigational safety and air pollution aspect of port
areas, and by completing a survey through Marine
Eye it will be possible to have an insight for all groups
of ships that navigate in port area. With features that
can improve, Marine Eye has a bright future.
As already mentioned, the Marine Eye system was
initially intended to monitor vessels in a certain part
of the sea surface. This system can be used in the
segments of maritime safety and sea transport. The
Marine Eye system can be capable for real-time
detection that will contribute to a further pollution
prevention of the sea surface, illegal anchoring and
illegal fishing. The system can also be applied in the
field of defence and maritime security. The data
collected by the Marine Eye system can be used by
specialized scientific institutions in the preparation of
maritime studies.
5 CONCLUSIONS
Application of smart buoy systems inside port
approaches and basins allowed continuous and
automatised data gathering of traffic and
environment. This novel, IoT-based device improved
ports navigational safety and ecological standards by
providing real-time and on-the spot survey of
shipping processes and its influence on the
environment.
As can be seen from the examples of different
smart buoy applications, the benefits of integrating
smart buoys in port systems are significant. The use of
such buoy-based systems offers the possibility of up-
to-date data collecting and autonomy of work, which
creates savings in time and money. But more
importantly, it provides users with a detailed and
relevant access to the information on which the
assessment of maritime safety and the port
environment is based. In addition, the flexibility of
technological solutions in creating a smart buoy
architecture allows for a large number of different
options for its design and application.
Deployment of the Marine Eye system in Trogir
port approach channel was initially intended to
monitor vessels in a certain part of the sea surface.
After conducted trial process, it was concluded that
system can generate photos of sufficient quality
despite the negative environmental influences, such as
sea waves. This system can be used in the segments of
maritime safety and sea transport by enabling real-
time monitoring and offering data for development of
navigational risk assessments. The Marine Eye system
will be able to detect and also prevent further
pollution of the sea surface, illegal anchoring and
illegal fishing, and with information about traffic it is
possible to conduct pollution inventories of port area.
Device can also be applied in the field of defence and
maritime security. Finally, the data collected by the
Marine Eye system can be used by specialized
scientific institutions in the preparation of maritime
studies.
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