Mainship 34 Trawler
2004–2009 · single Yanmar 370 hp · semi-displacement
Modern 34 Trawler · 2004–2009
Yanmar 370 hp, semi-displacement, ~20,000 lb, ~$150–200k. The exhaust riser is the watch item. This dossier.Classic 34 · 1978–1988
Perkins diesel, ~14,000 lb, ~$21–40k. Balsa deck-core rot is the defining issue. A different boat entirely.She clears every hard Loop gate with real margin, and a single Yanmar makes for simple, economical cruising. The watch items are model-specific and checkable: the raw-water exhaust riser (the standout) and prop cavitation. Neither is a dealbreaker — but the riser is the first thing to confirm on any hull.
The gates
What a Loop boat has to clear
| Gate | The number | Why it binds |
|---|---|---|
| Air draft | Under 19'6" | The Illinois River bridge at mile 300.6 — AGLCA calls it the lowest unavoidable fixed bridge on the Loop. There is no alternate route. Miss it and you cannot complete the Loop. |
| Water draft | Under 5' preferred | Trent-Severn carries a controlled depth of 6', and over 5' needs a signed waiver. The Rideau is maintained at 5'. The tightest published figure on the whole route is the New Jersey ICW at under 3' — which AGLCA pairs with local knowledge, and otherwise advises running outside in the ocean. Then the rivers and the Gulf ICW, where shoaling moves faster than the charts do. |
| Range | Plan 250+ nm | AGLCA names the long leg: Alton, IL to Paducah, KY — about 250 miles on their Inland Rivers page, ~240 in their FAQ. It shifts as marinas open and close, so verify current fuel stops. |
Only one of these is a wall. Over 5' of draft means a Trent-Severn waiver — a form, not a barrier, and AGLCA says outright that many boats drawing more than 5' have finished the Loop. Short range means carrying deck fuel, which AGLCA suggests itself. The Chicago River's 17' has the Cal-Sag Canal around it. The 19'6" bridge has nothing around it. That is the number to measure twice.
Scorecard
Gate by gate
| Criterion | Status | The read |
|---|---|---|
| Air draft | PASS | Published at 16'5"–17' (top of the flybridge) — clears 19'6" with ~2.5–3 ft of margin before you drop a single antenna. Sources differ slightly; get a tape on the specific hull, but this is a comfortable pass. |
| Water draft | PASS | 3'4" — well under the skinny-water line. Confirm loaded, but there's plenty of room. |
| Range | PASS | 250 gal; at trawler speed (~7 kn, ~3 gph) that's ~500+ nm — easily covers 250 nm legs. Caveat below: only at displacement speed. |
| Diesel | PASS | Single Yanmar 6LYA-series, 370 hp. Simple single-engine ownership. |
Risk 01
The raw-water exhaust riser
The one mechanical risk that defines this hull. Check it first.
Your move: confirm riser height · ask whether it's been extended · get the turbo's service/replacement history.
Risk 02
Prop cavitation
Your move: sea-trial at cruise and listen/feel for it · inspect prop and deadwood.
Risk 03
Fuel tank & engine controls
Your move: inspect the tank bottom where it sits · budget survey time for the controls and grounds.
Risk 04
Read the boat right
How to read this
Every claim wears its confidence
No owner-verified facts on this model yet — those get added as real owners confirm them, with a name and a date. This is the research-grade starting point, tagged honestly. An inference doesn't become a fact through confident phrasing; it becomes one when someone who owns the boat answers.
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