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Model profile · for Great Loop buyers
Mainship 400 Trawler
The published record on this model and what owners report, with the
questions worth asking while a boat is still a listing. This page covers the model.
Every boat still needs its own homework.
The published record
| Length overall | 41.33 ft |
| Beam | 14.17 ft |
| Draft | 3'8" |
| Fuel | 300 gal |
| Water | 130 gal |
Source: boats.com sea-trial spec box.
If a listing disagrees with these numbers, the listing may still be right. Settle the
difference before it costs you.
Clears the water gate with ease at 3'8". Air draft has no published basis at all, so this hull's own tape measure decides. Drivetrain choice and tank inspection are the rest of the homework.
Mainship's third-generation trawler (introduced 2003), purpose-built for exactly this kind of cruising, and orphaned with the rest of Mainship since 2012. The buy questions: what this hull carries aloft and how tall it really is, which drivetrain and what that choice traded, and the aluminum tanks' condition. Model fit and model risk only; condition is for a surveyor.
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How to read the tags on this page.
FACTdocumented, with the source named
CLAIMstated by one source, not yet confirmed
QUESTIONopen, and settled by looking at the boat itself
CONTEXTbackground on how this model is built or used
Sources are linked where published.
The published numbers
FACT
41'4" LOA, 14'2" beam, 3'8" draft, 24,000 lb; 300 gal fuel, 130 water.
The boats.com sea-trial spec box. The '400' name undersells the length: slips and haul-outs price the 41'4".
src:
boats.com sea trial (Tom Thompson)
From owners
CLAIM
The 8 kW Kohler generator in the lazarette is a tight fit to service
An owner of a 2005 400 reports that the top of the generator can't be reached with the sound shield on, and the coolant cap is hard to reach even with it off because of the deck overhead. The owner's workarounds: unbolt the generator, which is held by two bolts, so it can slide or pivot out as far as the fuel and exhaust lines allow, or cut an access hole in the deck above the coolant cap and fit a watertight deck plate. Reported at about 850 hours on the generator.
src:
Owner report: an owner of a 2005 Mainship 400 Trawler (Oct 2026)
Air draft
CONTEXT
No professional review publishes a bridge clearance for this model.
Neither the boats.com sea trial nor Yachting's review states one, and listing figures scatter (12'8" to 16'4" mast-down have both appeared). A folding radar mast was a factory OPTION, so hulls genuinely differ. Height figures are stated often and confirmed rarely; on this model there isn't even a stated factory number to argue about.
src:
boats.com options list (folding radar mast)
Your move: Establish what this hull carries aloft, whether the mast folds, and tape-measure everything-up before planning any fixed-bridge leg.
Tanks and systems
FACT
Two aluminum fuel tanks, mounted outboard.
Aluminum tanks have no fixed expiry, so inspect them rather than assume. Outboard placement decides what inspection access looks like on this hull.
src:
Yachting magazine review
Your move: Sight the tank bottoms and their outboard mounting areas at survey.
CONTEXT
The generator lives aft under the cockpit in its own compartment.
Good for noise at anchor; check it where it actually is: the afterdeck hatch, not the engine room.
src:
boats.com sea trial + Yachting review
Livability
CONTEXT
Two staterooms and one head, plus a reportedly spacious engine room even with the largest single.
boats.com found easy all-around access to every service point on the 385-hp single. Don't import other Mainships' engine-room reputations in either direction; open the hatch on this hull.
src:
boats.com sea trial
Buying
CONTEXT
Mainship has been an orphan brand since 2012.
The Luhrs Marine Group (Mainship, Silverton, Luhrs) filed for bankruptcy in 2012, having ceased powerboat production that January. The hulls didn't change; the parts-and-support questions are the standard orphan homework, and the owner community is large.
src:
Trade Only Today, 2012
QUESTION
The predecessor 390 has documented quirks. Ask whether this generation shares them rather than assuming either way.
The 390's record (public Trawler Forum testimony, held in its own profile) includes sealed-foam swim-platform flooding on original platforms and a wallowing gait in a following sea. The 400 is the third-generation redesign, not the same boat. The honest move is to put both to the seller and the sea trial: how does she run in a following sea, and what's the swim platform's construction and drainage story?
src:
Mainship 390 profile's Trawler Forum citations (predecessor scope)
CONTEXT
The record is quiet. We count that as a finding and state its limits.
In the professional reviews we've opened (the boats.com sea trial, Yachting's review) and the owner discussion gathered since, no recurring mechanical defect pattern has surfaced for the 400 the way one has for some contemporaries. That is an absence in what we've searched, not a guarantee about any hull. Individual boats fail surveys for individual reasons. The model's loudest open items are the unpublished air draft and the predecessor 390's separate record.
src:
scope: the sources this profile cites, searched through 2026-09
Engines
The engines research is part of the full profile inside the
product. It covers factory options, tested performance and the engine-specific
questions in our members' dossiers, and it travels with every dossier and survey brief
built on this model.
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