What are the risks and dangers of being in a drydock?

Posted by: Stuart Ribton
07 Jul 2026

A drydock is one of the most hazardous working environments in the maritime industry. Workers face a combination of height risks, fire hazards, toxic atmospheres, and heavy machinery in a compressed and often chaotic workspace. These dangers apply to everyone present during maintenance periods — from shipyard contractors and painters to yacht crew and visiting superintendents. The sections below break down the most common hazards and explain who is responsible for managing them.

What types of hazards are most common in a drydock environment?

The most common hazards in a drydock environment include working at height, hot work (welding and cutting), confined space entry, electrical hazards, falling objects, and exposure to toxic substances such as antifouling paints and solvents. During active maintenance periods, multiple trades work simultaneously in close proximity, which significantly increases the risk of overlapping hazards.

Drydock environments are inherently complex because so many different activities happen at the same time. A welder might be working on the hull while painters are applying solvent-based coatings nearby. Scaffolding goes up and comes down throughout the day. Contractors move heavy equipment across the dock floor while crew members try to access the vessel. This overlap means that a hazard created by one trade can directly affect another team working just metres away.

The physical environment itself adds to the challenge. Vessels are elevated on blocks, surrounded by scaffolding, and stripped of many of their normal safety systems while under maintenance. Bilges, tanks, and voids that are sealed during normal operation become accessible — and potentially dangerous — workspaces. Electrical systems are partially isolated, and temporary power supplies introduce their own risks.

Why is working at height so dangerous during a drydock?

Working at height during a drydock is dangerous because workers regularly access scaffolding, staging, and elevated platforms around a vessel that can be several metres above the dock floor. Falls from height remain one of the leading causes of serious injury in shipyard and drydock environments, and the risk increases when workers carry tools, work in poor weather, or operate on temporary structures.

Unlike a fixed building site, the scaffolding and staging in a drydock change constantly as the work progresses. Platforms are erected, modified, and dismantled throughout the maintenance period. This means the working-at-height risk is not static — it evolves every day. Workers may be familiar with a platform on Monday and find it has been reconfigured by Wednesday.

Yacht maintenance periods also often involve work on areas like masts, radar arches, and upper deck structures, which require working at significant height above a hard dock floor. Harness use, proper scaffolding inspection, and clear exclusion zones beneath elevated work areas are all important controls, but they rely on consistent enforcement across every contractor and crew member on site.

What are the risks of hot work on a yacht in drydock?

Hot work — including welding, cutting, grinding, and brazing — carries a serious fire and explosion risk in a drydock environment. Yachts often carry residual fuel, hydraulic fluids, and flammable coatings, and the hull and internal spaces can trap flammable vapours. A single spark in the wrong location can ignite a fire that spreads rapidly through a vessel stripped of its normal fire suppression systems.

Before any hot work begins, a formal hot work permit should be issued. This process requires checking the atmosphere for flammable vapours, removing or protecting nearby combustible materials, and having fire watch personnel in place during and after the work. The “after” part is particularly important — fires can smoulder for hours before breaking out, so fire watch duties do not end when the welding torch is switched off.

During maintenance periods on yachts, hot work is often needed for hull repairs, stern gear work, and structural modifications. The risk is not just to the vessel itself but to adjacent vessels in the shipyard and to the workers carrying out the task. Proper coordination between the shipyard, the yacht’s captain, and any management team overseeing the refit is important to make sure hot work is controlled and permitted correctly.

How do confined space hazards affect drydock workers?

Confined space hazards in a drydock affect workers who need to enter tanks, voids, bilges, chain lockers, and other enclosed areas of a vessel. These spaces can contain oxygen-deficient or toxic atmospheres, and they present serious risks of asphyxiation, poisoning, or entrapment. Confined space incidents are particularly dangerous because they can incapacitate a worker quickly, leaving them unable to self-rescue.

During a drydock, spaces that are normally sealed or inaccessible become work areas. Fuel tanks may be cleaned, ballast tanks inspected, and bilge compartments treated or repaired. Before anyone enters, the atmosphere must be tested for oxygen levels, flammable gases, and toxic substances. This is not a one-time check — the atmosphere in a confined space can change rapidly as work progresses or as residues off-gas.

Entry into confined spaces should always follow a formal permit-to-work system. This includes designating a trained attendant outside the space, establishing communication with the person inside, and having rescue equipment immediately available. Tragically, many confined space fatalities in industrial settings involve rescuers who enter without proper equipment and become victims themselves. Awareness of this risk is important for everyone involved in a drydock maintenance period.

Who is responsible for safety in a drydock?

Safety in a drydock is a shared responsibility. The shipyard holds primary duty as the host employer and controls the physical environment. The yacht’s captain and management team are responsible for the vessel itself and for ensuring that crew and contractors working on board follow safe systems of work. Individual contractors are responsible for the safety of their own personnel and activities.

In practice, this shared responsibility can create gaps. When multiple parties each assume that someone else is managing a particular risk, hazards go unaddressed. This is why a clear safety coordination structure matters during maintenance periods. Typically, the shipyard will issue a site induction, enforce permit-to-work systems, and manage access to the dock. The yacht’s management team should ensure that any work carried out on the vessel aligns with those systems and that the captain is informed of all activities taking place.

Flag state and class society requirements also impose safety obligations on the vessel itself. Depending on the vessel’s registry and the nature of the work being carried out, certain inspections, certifications, and safety procedures may be legally required before, during, or after the drydock. Staying on top of these obligations is part of responsible yacht ownership and management.

How can a yacht management company reduce drydock risks?

A yacht management company reduces drydock risks by providing experienced oversight throughout the entire maintenance period — from planning and contractor selection through to sign-off and sea trials. Having a knowledgeable superintendent or technical manager on site means that safety concerns are identified early, permit systems are followed, and the work progresses in a controlled and coordinated way.

Preparation before the drydock begins is where a significant amount of risk reduction happens. A well-prepared maintenance period includes a detailed scope of work, pre-selected contractors with verified safety records, and a clear schedule that avoids conflicting high-risk activities happening simultaneously. Arriving at a shipyard without a structured plan is one of the most common ways that drydock costs, timelines, and safety incidents escalate.

Our technical support services are built around exactly this kind of hands-on involvement. With a background in offshore engineering and decades of experience managing drydocks and refit projects, we understand the practical realities of what can go wrong — and how to prevent it. We work alongside shipyards, contractors, and classification societies to keep maintenance periods safe, efficient, and compliant.

Every vessel and every drydock is different. If you are planning a maintenance period and want experienced oversight from people who have managed these environments first-hand, get in touch with us and we will talk through what support looks like for your specific vessel and situation.

Frequently Asked Questions

How do I prepare my yacht crew for the specific hazards they'll encounter during a drydock?

Before the drydock begins, crew should receive a formal site induction from the shipyard covering site rules, permit-to-work systems, emergency procedures, and restricted areas. Beyond the shipyard induction, the captain should brief crew specifically on the vessel's own hazards — such as tanks being opened, electrical isolations in place, and areas where contractors are active. Crew who understand the hazard landscape are far less likely to inadvertently enter a dangerous space or interfere with a controlled work activity.

What is a permit-to-work system and why does it matter during a drydock?

A permit-to-work (PTW) system is a formal, documented process that authorises specific high-risk activities — such as hot work, confined space entry, or working at height — only after defined safety controls have been verified and signed off. In a drydock environment where multiple trades are operating simultaneously, PTW systems are the primary mechanism for preventing overlapping hazards from causing incidents. If a shipyard does not appear to be enforcing a structured PTW system, that is a significant red flag that should be raised before high-risk work begins.

What should I do if I notice a safety violation or unsafe condition during a drydock?

Any unsafe condition should be reported immediately to the shipyard's safety officer or site manager — do not assume someone else has already flagged it. On the vessel side, the captain or the appointed superintendent should be informed so they can follow up through the correct channels. In serious cases where there is an immediate risk of injury, work in that area should be stopped until the hazard is controlled. A good shipyard will welcome these reports; a reluctance to act on safety concerns is itself a warning sign about how the rest of the project will be managed.

Are there specific regulations or standards that govern drydock safety for yachts?

Drydock safety is governed by a combination of the host country's occupational health and safety legislation, the shipyard's own safety management system, and the flag state requirements applicable to the vessel. For commercially operated yachts, class society rules and MLC (Maritime Labour Convention) obligations may also impose specific requirements around work environments and contractor management. It is worth confirming before the drydock begins which regulatory framework applies to your vessel and ensuring that the shipyard's procedures are compatible with those obligations.

How can I vet a shipyard's safety standards before committing to a drydock there?

Before selecting a shipyard, ask to review their safety management system documentation, incident and near-miss records, and any third-party safety audits they have undergone. It is also worth speaking to other yacht operators or management companies who have used the facility recently — first-hand accounts of how safety is managed day-to-day are often more revealing than formal documentation. Visiting the shipyard in person before the drydock is the most effective way to assess the culture on the ground, including how workers behave, how the site is organised, and whether safety signage and controls are visibly in place.

What are the most common mistakes owners and captains make when planning a drydock?

The most common mistakes include underestimating the time and complexity of the scope of work, selecting contractors based on cost alone without verifying their safety records, and failing to appoint an experienced superintendent to oversee the project on site. Another frequent error is treating the drydock as purely a technical and logistical exercise, with safety coordination left entirely to the shipyard. Owners and captains who take an active interest in how safety is managed — not just whether the work gets done — consistently experience fewer incidents, fewer delays, and better outcomes overall.

What happens if there is a serious incident or injury during a drydock on my vessel?

In the event of a serious incident, the immediate priorities are emergency response, medical assistance, and securing the scene. The shipyard's emergency procedures will govern the initial response, and the relevant national authorities will typically be notified and may conduct an investigation. For the vessel owner and management team, there are also potential obligations to notify the flag state, class society, and insurers depending on the nature of the incident and the vessel's certification. Having clear lines of communication and a documented record of all safety measures in place before and during the drydock is important both for regulatory compliance and for any subsequent liability considerations.