Working Overside & Aloft: Safety Guide

Working overside — over the ship's side into the water — and working aloft in masts, funnels, and cranes are among the highest-risk activities in the maritime environment. Falls from height and man-overboard incidents during deck maintenance are recurring causes of serious injury and fatality at sea. Yet both activities are routine parts of vessel maintenance across all sectors.

This guide covers the safety requirements, permit-to-work procedures, PPE standards, weather and sea-state limits, and rescue planning that must be in place before any overside or aloft work begins.

Why These Activities Are High Risk

The combination of height, movement (vessel roll and pitch), environmental conditions (wind, sun, temperature), and the physical isolation of the work position creates a hazard profile that goes well beyond typical shore-based working-at-height situations. Add salt-corroded equipment, awkward access angles, and the ever-present possibility of falling into the sea, and the risk profile becomes clear.

Common causes of incidents during overside and aloft work include:

• Failure of staging, bosun's chairs, or securing arrangements
• Unexpected vessel movement causing loss of footing or balance
• Improper PPE — particularly fall arrest equipment not rated for the work position
• Working in deteriorating weather without monitoring
• No rescue plan in place before work begins
• Working alone without communication

The Permit to Work System

All work overside or aloft must be covered by a formal Permit to Work (PTW). This is not optional — it is required under ISM Code procedures and the SMS of any properly managed vessel. The PTW serves three purposes:

1. Forces a pre-work hazard assessment specific to the actual conditions on the day
2. Defines who is responsible for monitoring the work and the person working
3. Confirms that rescue arrangements are in place before work begins

The PTW must be signed off by the responsible officer (typically the chief officer for deck work) and must not be issued until all safety measures are confirmed in place. Work must stop if conditions change and the permit may need to be reissued if there is any significant break in the work.

Risk Assessment: What to Cover

A proper risk assessment for overside or aloft work addresses:

Environmental conditions

• Wind speed and direction — most operators set maximum limits around Beaufort 3–4 for aloft work and similar for overside
• Sea state and vessel motion — even apparently calm conditions can result in unexpected rolls
• Visibility — low visibility creates additional hazards if the vessel is moving
• Temperature — extreme heat causes fatigue and impairs judgement; cold reduces manual dexterity

Work position and access

• How will the worker be secured at the work position?
• What is the rescue route if the worker is incapacitated?
• Can the work be done from a safer alternative position?

Vessel status

• Is the vessel at anchor, alongside, or underway? (Work is generally prohibited when underway unless specifically risk-assessed)
• Are other deck operations running that could create additional hazards (mooring, cargo, crane operations)?
• Is the vessel taking ballast, which could affect stability and trim mid-job?

PPE Requirements

For working aloft

The minimum PPE for working aloft includes:

• Full-body harness — not a chest harness or safety belt. A full-body harness distributes arrest forces across the torso and thighs, reducing injury risk during a fall. It must be inspected before each use and have a current examination certificate.
• Shock-absorbing lanyard — with a length appropriate to the work position. The lanyard must be attached to a certified anchor point, not improvised rigging.
• Safety helmet — with chin strap secured
• Non-slip footwear
• Gloves — appropriate for the work being done
• Communication device — walkie-talkie or equivalent to maintain contact with the standby person

For working overside

• Full-body harness with lifeline attached to a secure point on deck above the work position
• Approved personal life jacket (PLJ) — worn, not just available
• Immersion suit or thermal protection depending on water temperature
• Waterproof communication device or whistle
• Bosun's chair or stage must be rated and inspected — never use improvised staging without a structural assessment

Anchor Points: What Counts and What Doesn't

One of the most common shortcuts in overside and aloft work is the use of unsuitable anchor points for lanyards and lifelines. A certified fall arrest anchor point must:

• Be designed and installed for that purpose, or assessed by a competent person as adequate
• Be capable of withstanding the arrest load (typically 15 kN minimum for a single-person anchor)
• Be positioned so that a fall is arrested before the worker contacts a hazard (working platform, water surface, etc.)

Railing stanchions, temporary cleats, and other deck furniture are generally not rated anchor points. Ship's rigging may or may not be suitable depending on its condition and configuration. If in doubt, the chief officer must assess the anchor point before the PTW is issued.

Standby and Monitoring

No person may work overside or aloft alone. A dedicated standby person must be positioned where they can maintain visual or voice contact with the worker throughout, and must have no other duties during the period of the work. The standby person's responsibilities include:

• Monitoring conditions — if weather or sea state deteriorates, work stops
• Maintaining communication with the worker at defined intervals
• Alerting the bridge immediately if the worker is incapacitated or falls
• Initiating rescue without entering the water themselves unless qualified and equipped to do so

Rescue Planning: Before the Work Starts

This is the step most frequently skipped, and the one that determines outcomes when things go wrong. Before any overside or aloft work begins, the responsible officer must confirm that:

• A rescue plan specific to this work position exists and has been briefed to the standby and bridge team
• Rescue equipment is on deck and ready — rescue line, life ring, rescue boat or man-overboard equipment as appropriate
• The bridge is informed of the work and knows to maintain contact
• For overside work, the rescue boat (if fitted) is in a ready state

Weather Limits

Most company SMS documents specify weather limits for overside and aloft work. Common limits include:

• Work aloft: maximum Beaufort 3 (wind speeds up to 10 knots) when underway; Beaufort 4 when at anchor in sheltered waters
• Work overside: maximum Beaufort 2–3 depending on sea state; no work alongside in ports with significant wash from passing traffic
• Lightning risk: all work must cease and personnel must descend from any elevated position

These limits are minimums. Local conditions, vessel type, and the nature of the work may require stricter limits. If in doubt, the chief officer's decision to cancel or postpone is always the right call — no maintenance job is worth a fatality.

Superyacht-Specific Considerations

On superyachts, mast work is a frequent requirement for maintenance, light replacement, and antenna work. The close quarters of marina berths introduce additional hazards (neighbouring vessels, passersby, overhead electricity cables). Some superyacht operators use contracted riggers for mast work rather than deck crew — if your employer does this, it is worth understanding why and applying the same caution to any work you are asked to do in their absence.

Before You Start: The Briefing

Every overside or aloft job, regardless of how routine it feels, requires a pre-work briefing with everyone involved. Cover:

1. The specific task and time expected
2. The hazards identified and control measures in place
3. PPE requirements — check and confirm before the person goes over the side or up the mast
4. Communication protocol and check-in intervals
5. The rescue plan — who does what if something goes wrong
6. Weather and conditions — what triggers stopping work

If you are the person going overside or aloft, it is your right — and your responsibility — to be satisfied that all of these are in place before you go. Stop Work Authority applies here as much as anywhere else on the vessel.