Sea Trial Scripts: The Hour That Validates a Listing
Updated: August 2026
A sea trial is not a boat ride. Run it as a script: cold start, staged load increases with readings recorded at each step, full-power run, manoeuvring, anchor deployment and recovery, then systems under real demand. Ninety minutes conducted this way exposes more than a full day spent admiring the vessel.
Before you leave the dock
Insist on a genuine cold start. A vessel warmed up before you arrive has concealed the single most informative moment of the day: how the machinery behaves from cold, how long it cranks, what the exhaust does in the first two minutes, and whether there are leaks that seal once the engine is warm. Arrive early and ask that nothing be started before you board.
Record the starting conditions: hour meter readings for the main engine and both generators, fuel and water tank states, and the number of people aboard. Every later reading is meaningless without them.
The load ladder
- Idle, ten minutes. Watch exhaust colour, listen for irregular running, check for leaks with the engine room open.
- Half load, twenty minutes. Record coolant temperature, oil pressure, exhaust temperature and shaft vibration.
- Three-quarter load, twenty minutes. The band the vessel will actually cruise at. Record fuel burn if a flow meter is fitted, and note the speed achieved.
- Full power, ten minutes. Not to admire the wake but to see whether the engine reaches rated revolutions. An engine that will not reach its rated speed is telling you about propeller pitch, fouling, or a tired engine.
- Return to idle. Watch temperatures settle and check the engine room again for anything that appeared under load.
Write the numbers down as you go. Memory is unreliable and the seller’s captain will be talking throughout.
Manoeuvring and steering
Run full lock to full lock in both directions and count the turns and the time. Check for hydraulic leaks at the ram and confirm the emergency tiller is present and fits. Execute a stop from cruising speed, then astern propulsion, and note vibration and any unusual noise from the sterngear. Hold a steady heading for five minutes and observe how much correction the helm needs; excessive correction suggests rudder, bearing or trim issues.
Anchor, ground tackle and deck systems
Deploy and recover the full anchor chain. This is skipped on most trials and it should never be. It reveals windlass condition under real load, the actual chain length against the claimed length, chain and shackle condition, and whether the crew have a working procedure. A windlass that struggles to recover in calm conditions will not perform on a night when it matters.
While at anchor, run the tender: launch it, start it, and recover it. Tenders are frequently listed as included and frequently not operational.
Systems under real demand
- Air conditioning in every cabin simultaneously, for at least thirty minutes.
- Both generators individually carrying the full domestic load — see generator redundancy.
- Watermaker producing, with output measured and product water tested.
- Bilge pumps and alarms tested individually, not assumed.
- Navigation and communications powered up and used, including radar and AIS.
- Galley equipment and refrigeration running while the air conditioning is at full demand, which is when weak electrical installations reveal themselves.
Who should be aboard
Your surveyor, an engine specialist if the machinery is large or complex, and you. Keep the party small and purposeful. The seller’s captain should run the vessel, because watching how a professional handles the hull tells you a great deal, but the script should be yours and the readings should be recorded by your side.
Afterwards, get the trial observations written into the survey report rather than left as a verbal impression. It becomes part of the file you negotiate against, alongside the costed defect list described in choosing a surveyor.
Conditions matter, so choose them
A trial run in flat water inside a harbour tells you almost nothing about sea-keeping. Ask for at least part of the run in open water with some swell, and take the vessel beam-on for a few minutes to observe the roll period and how quickly it damps. On a beamy phinisi with a high superstructure this is the moment that either reassures you or does not. If the seller declines open water on a calm day, ask why. The honest answers — a certificate limitation, a known steering issue, a crew shortage — are all things you needed to know before the trial rather than after it.
Request the vessel dossier
We arrange full sea trials with cold start, load ladder and anchor deployment on request. WhatsApp +62 811-3941-4563 or write to [email protected]. All figures on this site are quoted in USD.
Frequently asked questions
How long should a phinisi sea trial take?
Ninety minutes to three hours conducted as a structured script. The duration matters less than the sequence: a cold start, staged load increases with readings recorded, full power, manoeuvring, and anchor deployment and recovery.
Why does a cold start matter so much?
Because it exposes cranking behaviour, first-minute exhaust colour and leaks that seal once the engine warms. A vessel started before you arrive has concealed the most informative two minutes of the trial.
Should the anchor be deployed during a sea trial?
Yes, and it is routinely skipped. Full deployment and recovery tests the windlass under real load, verifies actual chain length against the claim, and reveals chain and shackle condition.
What readings should I record?
Hour meters at the start, then coolant temperature, oil pressure, exhaust temperature, shaft vibration and achieved speed at each load step, plus tank states. Written numbers, not impressions.
Phinisi Boat For Sale is a specialist maritime brand and digital platform under Juara Holding Group. Vessel-sale, construction, refit and repair contracts are issued by PT Komodo Galangan Nusantara. Brokerage, central agency and charter-marketing contracts are issued by PT Komodo Bahari Nusantara. Separate contracts, separate fees, separate ledgers.
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Written and checked by the desk. Figures are dated at the point of writing — our editorial standards explains how, and what happens when something here turns out to be wrong.
