The sea trial checklist

Before leaving the berth

1. Check the bilge is dry, the engine oil and coolant levels, and the gearbox oil.
2. Open the seacocks, and check the raw-water strainer.
3. Start the engine from cold. Note how quickly it starts and what comes out of the exhaust.
4. Watch the gauges: oil pressure, temperature, charging.
5. Test the bow thruster, the horn, and the lights.

Under power

• Ahead and astern. The gearbox engages without a clunk.
• Steering lock to lock. It moves smoothly, with no noises.
• Increase speed slowly to cruising rpm and hold it. Look for vibration, noises and gauge changes.
• Full throttle for 5 to 10 minutes. The engine should reach the rated speed in the maker's data. If it does not, the cause may be fouling, a worn propeller, a wrong propeller, or engine trouble. Temperatures stay steady and the exhaust is clear.
• Back off and idle. It idles smoothly.
• Stop and restart the engine when hot.

Under sail

1. Raise the mainsail, unroll the genoa, and check winches, clutches and furling.
2. Sail upwind and downwind. Note weather helm, speed and how the boat handles.
3. Reef and shake out the reefs.
4. Tack and gybe.

Systems

• Autopilot holds a course and tracks a turn.
• Chartplotter, depth, speed, wind, radar and AIS give plausible readings.
• Windlass runs and holds.
• Air conditioning, generator and refrigeration work.

After the trial

1. Inspect the engine room while the engine is hot, for leaks.
2. Check the bilge again.
3. Note the engine hours before and after. See Engine hours, and whether they can be trusted.
4. Make a list of anything that failed or looked wrong, and send it to the surveyor.

Practical points

A trial takes two to three hours. Choose a day with moderate wind, since light air hides faults and a gale ends the test. Agree who pays for fuel and the berth beforehand. See Survey and sea trial: how it works, who pays, what happens next.

Related guides

• Survey and sea trial: how it works, who pays, what happens next
• Mechanical survey and oil analysis
• Post-survey renegotiation: reduce, repair or walk away