Every sea trial is a way to gather evidence. Feeling how the trawler you’re thinking about buying travels through the water and behaves at different speeds is an essential part of your evaluation.

In a different world, you might spend all day, or even a long weekend, covering dozens of miles to learn as much as possible. In reality, the sea trial is part of a busy pre-purchase survey, and it is often a simple jaunt from the marina to the haulout yard and back to the home slip. The seller does not want to put the trawler in bad sea conditions, so the weather during your survey may also limit where you can run. If you want to head out beyond protected waters, this needs to be agreed upon in advance, if you can even fit that kind of run into the pre-purchase schedule.

Still, experiencing the ride will likely make it easier for you to render a verdict about the boat. The sea trial is normally the most convincing part of every trawler transaction, for better or worse.

Here are some factors to consider during your short time away from the dock.

Cold Start

Your surveyor and diesel mechanic need as long as two hours in the engine room before start-up. They are looking for leaks, drips and other clues while checking coolant levels, oil levels, fuel valves and machinery condition. Wait until they are finished before turning on machinery.

Start-up

Follow the owner or captain around to witness his pre-departure engine room routine and his procedures in the pilothouse. Observe the sequence of button-pushing, breaker-flipping and turning keys. Take notes.

Safety Review

While the trawler is warming up, and before you depart from the dock, the captain should show you the location of life jackets and first aid gear.

Stopping

It may be advantageous to anchor out, to test the windlass and ground tackle. This is often a convenient time to launch the dinghy, ensuring that the davit or lift are in proper working order.

Haulout

When the trawler is out of the water, check the underbody appendages. Do a power wash if the bottom is dirty so you can see how the boat runs on a clean bottom.

Underway

Walk through the trawler to become accustomed to sound levels and to get a feel for the motion. When away from shore power, the alternators need to be charging. The generator should be running. Test the air conditioning, watermaker, laundry and everything else that should be working. Operate the thrusters and stabilizers. The diesel mechanic should spend most of his time in the engine room. Bring your own ear protection and an infrared temperature gun.

Steering

It’s important to operate the trawler from all helm stations. Conduct a series of S-turns and circles in both directions with someone observing the rudder post and steering ram. Review the number of turns from lock to lock and the vessel’s turning radius.

Propulsion

The main engine(s) need to be run from idle through wide open throttle. Check the rated rpm, pressures, vibrations, loads and alarm systems. A back-down test involves running slowly, shifting to neutral and then easing into reverse. It’s an important way to determine the longevity of the engine mounts.

Navigation

Power on and operate all instrumentation: radar, chartplotter, autopilot, VHF radio and depth sounder. The surveyor will power up the displays, but typically does not dive into the options menus to test settings.

Hands-on

In open water, with no obstructions, it is imperative to have some tiller time. Get a feel for how the boat responds under the watchful eye of the captain.

After returning to the dock, it’s cross-examination time: Review what the survey team found. Listen closely to their counsel, and express your thoughts and concerns.

Then, like any good judge or jury, draw your own conclusions. Your opinions overrule all other factors. Declare the case closed either way and, hopefully, head off for paradise.  

This article was originally published in the October 2023 issue.