Sailboat Sea Trial Log PDFTimed Performance & Handling Record

A sea trial is the only part of a purchase that cannot be repeated later for free.

Three hours on the water, and most buyers come home with a feeling. She sailed nicely. The engine seemed fine. Something was vibrating, somewhere, at some revs. None of that survives a negotiation, and none of it can be compared against the next boat you look at.

This log replaces impressions with figures. Every reading has a line, every line has a unit, and the day ends with a record you can set beside another vessel, beside the builder's own data, or beside the same boat a year later.

A speed logged on one heading carries the tide inside it. That single omission is why most sea-trial numbers are worthless the moment you try to compare two boats. This log asks for both headings on every step of the RPM ladder, and model S2 averages the pair.

The same discipline runs through the sail section: one full minute settled at working trim before you read a number, and the trim recorded beside every figure. A speed without its sail state is an anecdote.

In the Fillable edition every line has a tick box and a field, sized for a thumb rather than a stylus. Tick a line as you do it, type the reading beside it; in Adobe Acrobat Reader, free on computer, iPhone and Android, the mean speeds, the eight models and the reduction sheet fill themselves. The Pencil & Print edition is ruled for handwriting in GoodNotes or Notability, or on a clipboard in a wet cockpit. Both come in A4 and US Letter and work offline.

The buyer with one trial and no second chance. Work in the printed order and do not let the broker set the pace. The cold start comes before anything else, and the pressure to skip it is exactly why it gets skipped. You will not get that engine cold again before you have paid.

The cruising buyer. Your boat will spend more of her life motoring into a crowded harbour than beating to windward. Stopping distance and turning circle, reduced to hull lengths, tell you more about the next ten years than the pointing angle does.

The racing buyer or the owner before a refit. Eight upwind runs with the trim recorded beside each, and a minute settled before you read. That is a baseline you can hold a new sail or a new bottom against afterwards, which is the only way to know whether the money bought speed.

The buyer comparing two boats. Reciprocal headings on every step, or you are comparing two tides rather than two hulls. This is the one discipline that makes two trials on two different days genuinely comparable.

The delivery skipper. You are handing back a vessel and want the record to speak for you. Figures with times and conditions against them end the conversation about what happened; a shrug invites it.

The Due Diligence Kit records what you find standing still. This log records what she does moving. The Purchase Budget Worksheet prices whatever either of them turns up.

Each works alone. Used together they cover a purchase from the first email to the signed offer, and they share the same recording conventions so the findings carry across without retyping.

This log records measurements and observations that you take. It does not judge them, and it reaches no conclusion about any vessel. It is not a marine survey, not a valuation, and not engineering or navigational advice.

A sea trial is conducted at sea. The skipper remains solely responsible for the vessel, for everyone aboard, for the decision to leave harbour and for every manoeuvre attempted. Nothing in this document instructs you to attempt any manoeuvre in any condition, and no entry in it should ever be completed at the expense of a proper lookout.

Instant download. Your links appear on screen the moment payment clears, and a copy arrives by email, usually within a few minutes. They do not expire.

2026 Edition, Revision 2.1, AML-STL-2026-01. Apex Marine Labs designs the organisational process behind good seamanship. Our documents record and organise; they do not replace a certified marine survey, nor professional advice. Apex Marine Labs does not survey vessels or assess their condition.