Highlights

• Remote and automated inspections are associated with financial and safety benefits, including savings in harbor costs and the potential to detect critical elements with greater certainty, which remains to be investigated.
• An interaction with hull monitoring is described, since indications of changes in stresses or accelerations identify the areas that remote or automated inspections should examine more closely.
• Digital twins are presented as closely connected to hull monitoring because, without sensors and instrumentation, no physical twin exists and no digital twin can be established.
• Hull monitoring and digital twins are both positioned to support decisions and actions, including improved use of the vessel and the tailoring of inspections and surveys.
• Financial benefits are expected in most cases when these approaches are applied smartly, together with increased safety.

Highlights

• A digital model is defined as a drawing, computer simulation, finite element, or CFD representation without any effect from the physical object, so a finite element ship model is not a digital twin.
• A digital shadow is defined by a one-way data flow, in which a change in the state of the physical object is reflected in its digital copy, with no feedback in the other direction.
• A digital twin is defined by a two-way data flow, in which the digital copy receives the physical states, processes them, and returns newly generated data as a basis for decisions.
• Two architectures are described, one for the ship life cycle and one for a machinery unit from the electric motor to the propeller, both starting from a sensor-instrumented physical twin.
• Decision support is produced as the output, such as speed reduction under high structural load, with cloud computing, internet of things, machine learning, and big data enabling real time exchange.

Highlights

• Hull monitoring is motivated by safer, more cost-effective operations, better assessment of operational risks, and support for docking schedules and capital expense planning.
• Improved knowledge of structural loads in ice is presented as enabling higher speeds when required and speed reductions at other times to limit fatigue loading.
• A lack of information on the bridge about the actual hull load is identified as a long standing challenge, and percentage based output is reported to be preferred over traffic light indications.
• Instrumentation is limited by inaccessible locations, the need for external voltage supplies and cabling, sensor deterioration in corrosive tanks, and data stored only at coarse intervals.
• Sparse monitoring with up to six sensors on longitudinals is contrasted with denser layouts required for slamming and fatigue, while around 100 vessels are reported to hold a DNV hull monitoring notation.

Highlights

• An older classification society image of a bulk carrier cargo hold is presented, showing a vehicle with a hydraulic crane that still requires a person to operate it.
• Automated inspections are described as operating fully independently of human intervention, as illustrated by a climbing robot mounted on the outer hull in a European Union project.
• Autonomous units are expected to use non-destructive testing devices, collect and automatically process data using algorithms, and enable evaluation from a safe, stationary location.
• Target defects include general, pitting, weld metal, and grooving corrosion, cracks, deformations, coating breakdown, and fouling, with cracks difficult to distinguish from cracked paint.
• Three challenges are defined as complete data collection, prompt and correct identification requiring significant computing power, and the assessment of localized findings for structural decision-making.

Highlights

• Remote surveys are addressed in IMO guidelines covering the examination of the hull structure, machinery components, and other systems, with the hull structure as the main focus.
• No physical attendance of a surveyor is required, while a trained or competent crew member or qualified technician and two-way audio and video communication are required.
• Reporting requirements include the type and age of the ship, justification for the remote method, items verified remotely, consultation with the flag administration, personnel training, and information transparency.
• Five randomly selected flag state rule sets were found to accept remote surveys, indicating that the practice is becoming increasingly established.
• Limitations are identified in unstable connectivity within voids, in tanks in use, in watertight voids requiring eight to twelve hours of ventilation, and in safety certificates and ISM shipboard audits that cannot be fully replaced.

Highlights

• Key terms are introduced, covering instrumented hulls, hull monitoring, digital twins, decision-making and actions, remote and automated inspections, and financial and safety benefits.
• Traditional inspections by classification societies are described as requiring surveyors to board and enter voids and tanks, with the work presented as tedious, dangerous, and expensive.
• Costs are attributed to the time allocated to surveys, possible delays at the port, and surveyors' travel expenses.
• Special surveys are carried out every five years, together with intermediate surveys and less formal condition surveys requested by the owner or the charterer.
• Remote surveys are defined as surveys conducted from an office, with trained personnel on board, and with some inspections possible while the ship is at sea.

Highlights

• Three recurring challenges are identified across the seven studies: resource constraints that may exclude smaller shipping companies and fishing fleets, privacy and data governance across jurisdictions, and physiological side effects such as monitoring-induced stress
• Cross-jurisdictional data flows involve frameworks like GDPR, IMO guidelines and UNESCO AI ethics recommendations, with blockchain proposed for secure records though governance frameworks are still being written
• The economic case is concrete, avoiding medical evacuations at about 100,000 dollars and mental health repatriations at 168,000 dollars each, while the value proposition aligns across seafarers, ship owners, healthcare providers and vendors
• Six open frontiers are outlined, including adaptive architectures, integration with electronic health records, federated learning, reconfigurable digital twins, seawater field validation and larger randomized controlled trials
• Evidence exists at three scales, engineering prototypes, a clinical pilot and the Navy fleet deployment, yet even with 845 participants the field is still answering feasibility rather than effectiveness, and the acceptable latency question remains unresolved

Highlights

• The largest field study to date was a US Navy deployment by Kubala and colleagues, published in Applied Ergonomics in 2024, covering 845 active duty sailors across five warship cohorts and over 10,000 person-days of continuous data
• Each sailor wore an Oura Ring and a Readyband simultaneously, with malfunction rates of about 1.2% and 2.2%, and wear prevalence of roughly 69% and 71%, showing the hardware works despite ship motion and salt water
• Feedback was found to drive usage more than battery life, since the Oura's daily summaries encouraged wear despite frequent charging, while older sailors used both devices more consistently than younger ones
• Four lessons are drawn: form factor must match the job, user feedback drives use, adoption is a social process needing onboard support, and genuine workforce demand exists, but trust must be earned
• A Korean pilot study by Kim, Park, and colleagues in 2025 with 11 seafarers over 12 weeks showed statistically significant blood pressure reductions, though only three participants, all with prior experience, wished to continue afterward

Highlights

• The digital twin concept was introduced by Michael Grieves in 2003 at the University of Michigan, later adopted by NASA in 2012, with the human digital twin formally defined in 2021 and brought into the maritime context through the Mariner 4.0 framework in 2022
• A human digital twin in maritime is described as a real-time digital replica of a seafarer, updated continuously across physiological, behavioral, and environmental data, capable of simulation and prediction
• Three distinguishing capabilities are outlined: simulation of a specific body's response using finite element methods, personalization through individual baselines, and prediction that flags risk before symptoms emerge
• In classical machine learning, decision trees reach 82.6% on fatigue detection and naive Bayes 85.5% on stress, while deep learning and hybrid models perform higher, such as LSTM-based fatigue detection reporting 99.9%
• Caution is urged that very high accuracy figures may reflect overfitting on small datasets, and that accuracy does not equal generalization across populations, conditions, and real-world variation

Highlights

• Maritime data transmission is divided into two parts: onboard transmission from sensor to a local hub, and ship-to-shore transmission from the vessel to land-based analytical centers
• For onboard options, Zigbee and Bluetooth suit short-range sensor networks, Wi-Fi handles larger data sets, and UWB scores highest by combining range, speed, and low latency, while NFC is essentially useless at this scale
• Ship-to-shore communication relies on low-earth-orbit satellites, and falling satellite costs are making continuous health monitoring of distant vessels increasingly available
• An open question is posed about the maximum acceptable latency between a vital sign deviation and a shore-based decision, which the field has not yet decided, and which limits full system design
• A comparative evaluation from a 2025 review scores five wireless technologies, with UWB leading at 4.6 out of 5, followed by Zigbee at 3.8, Wi-Fi at 3.6, Bluetooth at 3.4, and NFC at 2.2

Highlights

• Three categories of measurement are identified: physiological vital signs, psychological indicators, and comfort factors. Mental health among seafarers is noted as one of the most under-monitored areas in the industry
• Consumer wearables are shown to fail in maritime conditions, so devices must be waterproof, EMI-resistant, vibration-tolerant, low-power, and corrosion-resistant. Optical fiber sensing is highlighted as a promising next-generation substrate
• A low-cost system by Daniel and colleagues at the University of Kuala Lumpur in 2024 uses an Arduino Uno, thermistor, and pulse oximeter for about 50 dollars, recording an average resting pulse of 77.8 beats per minute and a body temperature of 36.7 Celsius
• A waterproof device for offshore divers by Barbosa and colleagues at PUC-Rio in Brazil uses a chest belt with an RS-485 connection over the umbilical cable, showing that wired transmission often beats wireless since Bluetooth does not propagate through water
• A triboelectric smart mat by Wang and colleagues, published in 2022, identifies people by their gait with 94.44% accuracy using a neural network, reframing the problem from measuring the person to measuring the space

Highlights

• The use of wearable technology for real-time health monitoring of seafarers is examined through a review of seven recent studies, ranging from Arduino-based prototypes to a US Navy study involving 845 sailors
• The scale of the problem is illustrated with over 50,000 vessels and nearly 2 million seafarers operating globally, while between 60 and 90% of maritime incidents are attributed to human error, such as fatigue, stress, and cognitive load
• An economic dimension is highlighted, with a single medical evacuation costing about 100,000 US dollars, and each mental health-related case estimated at approximately 168,000 dollars for shipping companies
• Maritime conditions are described as fundamentally different from land, including prolonged isolation, confined quarters, disrupted circadian rhythms, and environments hostile to electronics, so land-based wearable frameworks do not translate cleanly
• A five-stage pipeline called Human Digital Healthcare Engineering is introduced from a 2025 review, covering sensing, data transmission, human digital twins, AI-driven diagnostics, and predictive health analysis toward proactive care

• An integrated pathway is presented in which low carbon fuel, strategic infrastructure, and digitalization are combined to achieve maritime decarbonization. A coordinated system approach is emphasized rather than isolated solutions
• The absence of a single solution is highlighted, and a diverse portfolio of pathways is defined as necessary for both immediate deployment and long-term transition. A balance between practicality and scalability is established as a central objective
• The alignment of fuel, infrastructure, and digital innovation is framed as essential to transform decarbonization goals into operational reality. Cross-sector coordination among ports, policy makers, and maritime stakeholders is emphasized
• Global commitments such as emission reduction targets and green shipping corridors are positioned as key drivers of the integrated transition. Collective action across international stakeholders is identified as necessary for achieving these goals
• Early adoption of integrated strategies is associated with competitive advantage, enabling ports and maritime nations to shape future trade flows and secure long-term relevance. Decarbonization is positioned as both an environmental imperative and an economic opportunity

• The role of digitalization and innovation as the integrating pillar of maritime decarbonization is emphasized, enabling complex and electrified port systems to operate efficiently. Data, automation, and advanced analytics are positioned as essential for scalable emissions reduction
• Digital twins are virtual replicas of port infrastructure that enable real-time monitoring, simulation, and optimization of operations. Emissions reduction is achieved through improved coordination, reduced congestion, and predictive maintenance
• Data-driven port management systems are highlighted as tools for integrating vessel movement, energy consumption, and operational performance into a unified platform. Enhanced transparency and real-time carbon tracking are identified as critical for regulatory compliance and decision-making
• The integration of artificial intelligence and Internet of Things technologies is emphasized for predictive maintenance, smart energy management, and sensor-based monitoring. Operational efficiency and emissions reduction are achieved without compromising performance
• A comprehensive digital transformation strategy is outlined, including advanced management systems, blockchain-based traceability, and industry collaboration. Digitalization is positioned as a fundamental enabler of decarbonization, governance, and long-term competitiveness

• The critical role of strategic infrastructure development is emphasized, underscoring that low-carbon fuels alone are insufficient without supporting port capabilities. Ports are positioned as key enablers in energy transition, influencing fuel availability, operational efficiency, and emissions reduction
• Early investment in green infrastructure, including electrification, shore power, and green bunkering facilities, is presented as essential for supporting next-generation vessels. Competitive advantage is associated with ports that align infrastructure with decarbonization goals and future trade routes
• Electrification is identified as an immediate, deployable solution within port boundaries, enabling reductions through electric cargo-handling equipment, electric vehicles, and hybrid marine support vessels. Integration of renewable energy sources is emphasized to ensure genuine emissions reduction
• The concept of smart ports is introduced, where digital infrastructure, such as digital twins, enables real-time monitoring, operational optimization, and data-driven decision-making. Improvements in efficiency, emissions reduction, and asset management are linked to digitalization
• A structured pathway for infrastructure development is outlined, including expansion of green bunkering, scaling electrification, prioritizing shore-to-ship power, and enhancing intermodal connectivity. Strategic investment is framed as both an environmental necessity and a driver of long-term competitiveness

• The central role of low-carbon fuel solutions in maritime decarbonization is emphasized, with fuel choice identified as a determining factor for achieving climate targets. A portfolio approach combining immediate bridge fuels and scalable zero-carbon solutions is presented
• A lifecycle-based emissions perspective is introduced through well-to-wake analysis, enabling comparison of fuel options across upstream and downstream impacts. Green hydrogen and green ammonia are positioned as long-term zero-emission solutions requiring new vessel designs and infrastructure
• Biofuel is highlighted as a practical, immediately deployable pathway that enables emissions reduction with minimal or no retrofitting of existing vessels. Its role as a transitional solution supporting energy security and green economic growth is emphasized
• Green methanol is identified as a scalable near-term solution due to its familiarity with liquid handling and compatibility with existing infrastructure. Its potential to support net-zero pathways while attracting industry investment is underscored
• A layered transition strategy is outlined, integrating multiple fuel pathways aligned with vessel types, trade routes, and time horizons. The importance of research, supply chain development, infrastructure investment, and policy support in advancing low-carbon fuel adoption is emphasized

• A strategic roadmap toward a greener future for the global port and maritime industry is presented, emphasizing the sector’s role as the backbone of global trade. A critical turning point is highlighted due to rising demand and increasing pressure to reduce emissions
• A coordinated approach is outlined that achieves decarbonization through low-carbon fuels, strategic infrastructure development, and digital innovation. Environmental responsibility is aligned with competitiveness and economic resilience
• The urgency of decarbonization is emphasized, and a diverse portfolio of pathways is identified as necessary rather than a single solution. A practical and scalable transition toward a low-carbon maritime sector is framed as achievable
• The contribution of global shipping to greenhouse gas emissions is quantified at nearly 3%, with future increases expected without decisive action. Alignment with international targets and collaboration among stakeholders are identified as essential
• Global momentum toward decarbonization is reflected in national roadmaps, emission-reduction targets, and the development of green shipping corridors. Early action is positioned as a source of competitive advantage in shaping future trade flows and maritime relevance

• Maritime digitalization is structured around digital technologies and smart systems, human safety and regulatory integration, and capacity building with sustainability considerations.
• Future digital transformation is influenced by shared socioeconomic pathways, where factors such as population growth, economic growth, energy decisions, and education shape digitalization and digital inequality.
• Developing maritime economies are characterized by rising exports of ocean-related goods, indicating significant potential for further growth.
• Capacity building is defined as a set of procedures to develop skills, instincts, abilities, resources, and processes that enable societies to survive, adapt, and thrive in a digitalized economy.
• Barriers including institutional, infrastructural, cyber security, and sociopolitical challenges are identified, while partnerships for the goals are emphasized as a key element for advancing development.

• Capacity building is supported through the dissemination of standards that contain knowledge and best practices, enabling developing economies to benefit from shared experience and structured development approaches.
• Standards are organized into key areas, including well-being, risk management, government capacity, and economic growth, covering health, education, financial stability, governance, and international connectivity.
• Partnerships for the goals are emphasized through sustainable development frameworks, promoting official development assistance, financial support, and international cooperation in science, technology, and innovation.
• The dissemination of environmentally sound technologies and the establishment of a technology bank are identified as mechanisms to improve access to knowledge and support efficient and sustainable development.
• Multistakeholder and public-private partnerships are highlighted as essential for increasing exports, strengthening global trade participation, and ensuring coordinated development among governments, industry, and academia.

• Capacity building is defined as the development of skills, instincts, abilities, resources, and processes, aiming first for survival, then adaptation, and ultimately the ability to thrive through digitalization.
• Constructive procedures such as research, innovation, data collection, and analysis are identified as essential for enabling the transition toward digitalization by strengthening internal capabilities.
• Barriers to digital transformation are categorized into institutional, infrastructural, cybersecurity, economic, technological, and social factors, including governance fragmentation, poor internet connectivity, insufficient investment, and a shortage of skilled personnel.
• Cybersecurity risks are highlighted through examples of attacks that cause data loss, operational disruption, and significant economic losses, underscoring the vulnerability of maritime systems.
• Additional challenges, such as the gender gap in labor force participation and constraints on decarbonization, are identified, with digitalization, education, and policy measures identified as supporting factors for improvement.

• Developing economies are characterized by limited per capita resources, economic imbalance, illiteracy, high infant mortality, poor infrastructure, and low personal incomes, resulting in limited choices and a reduced quality of life.
• Developing maritime economies are described as increasing their role in exports of ocean-related goods and services, contributing to economic resilience, and creating job opportunities despite existing challenges.
• Export patterns are concentrated in specific sectors, such as ships, ports, and equipment, creating risks that necessitate diversification to enhance resilience against future economic changes.
• Small island developing states are highlighted for their high per capita participation in ocean trade, while they are exposed to significant risks, particularly related to climate change.
• A global shift in maritime trade participation is indicated, with developing economies increasing their share while developed economies decrease, alongside regional variations across Asia, Europe, the Americas, Africa, and Oceania.

• Shared socioeconomic pathways are possible futures shaped by interacting factors such as land-use change, pollution, health, greenhouse gas emissions, economic growth, demographics, urbanization, and energy systems.
• Different future scenarios are constructed based on variations in population growth, education, technological development, and energy transition, including scenarios with fossil fuel dominance or renewable energy adoption.
• Digital transformation level is expressed as an index that varies by country and time, incorporating GDP per capita, population, research and development intensity, and other factors.
• Digital inequality is a potential outcome of disparities in economic growth and rapid population growth, leading to uneven levels of digitalization across countries.
• Capacity building is emphasized as a necessary approach to reduce differences in digitalization levels and to prevent unequal digital transformation among global populations.