Dock Trials

What are dock trials?

Dock trials - also called harbour acceptance trials or alongside trials - are the structured programme of system tests carried out at the builder's quay before a newly built yacht goes to sea for the first time. They are the bridge between construction and operation: the point at which every system installed during the build is energised, calibrated, integrated, alarmed and tested under controlled conditions, with the yacht still safely tied to the wall. The programme is run by the yard's commissioning team in conjunction with the owner's representative, classification society surveyor and flag-state inspector where applicable.

The scope is comprehensive. Main engines and generators are started, run through their power curves, checked for vibration, temperature and exhaust performance, and run together to verify load-sharing. HVAC and chilled-water systems are commissioned room by room. Plumbing - fresh water, black water, grey water, sewage treatment - is filled, pressure-tested and put through full operating cycles. Audio-visual, lighting control, IT networks and entertainment systems are installed, configured and demonstrated. Navigation, communication, bridge integration and automation systems are integrated and tested. Crucially, alarm matrices and emergency shutdowns are exercised - fire detection, bilge alarms, engine shutdowns, watertight door operation - to confirm that the yacht behaves correctly under fault and emergency conditions.

Dock trials are required before the yacht can proceed to sea trials, and many findings from the dock-trial phase are corrected or refined before the yacht ever leaves the basin. The programme typically runs over several weeks on a large new build and produces an extensive snag list that must be closed before commissioning hand-over.

Why it matters for yacht owners

Dock trials are the owner's most important opportunity to see how the yacht actually performs before accepting delivery. Issues identified alongside - where the yacht can be opened up, parts swapped and systems re-tested without the cost and disruption of putting back to sea - are dramatically cheaper and faster to resolve than the same issues discovered after delivery. A thorough dock-trial programme, with the owner's project manager and technical adviser present, typically reduces post-delivery warranty work substantially and underpins a clean commissioning hand-over. Owners should expect the yard to provide a detailed test schedule and to invite owner-side witnesses to the critical milestones.

Key facts

• Dock trials are the structured pre-delivery testing of all yacht systems while alongside at the builder's quay.
• Also known as harbour acceptance trials or alongside trials.
• They precede sea trials and are required before the yacht can be commissioned and handed over.
• The scope covers main engines, generators, HVAC, plumbing, sewage treatment, electrical, AV, IT, navigation and communication systems.
• Alarms, emergency shutdowns and integrated safety systems are exercised under fault conditions to verify correct response.
• Classification society surveyors and flag-state inspectors typically witness key milestones.
• A dock-trial programme on a large new build typically runs over several weeks and generates a detailed snag list.
• Issues identified alongside are substantially cheaper and faster to resolve than the same issues found after delivery.