A reader sent this one in. One public listing, worked against the published record from the desk, before any deposit or travel money moves.
She fits the Loop's bridges with room to spare, and the question a buyer has to answer is the layout. Tiara built the 3700 Open with one private stateroom and one head. For a couple on their own that can work for a year aboard. For anyone who plans on guests, it's the whole conversation.
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Credit where due: this is a complete listing where it counts. It names the engines, twin Cummins 6CTA 8.3L diesels at 430 hp each, with 975 hours on both. It gives the generator, a Westerbeke 8.0 BTD with 581 hours. It states all three tanks: 411 gallons of fuel, 98 of water, 40 of holding. It states the draft, the beam, the dry weight and the deadrise. It describes a private master stateroom with a queen berth, a convertible dinette, and a large head with a separate stall shower. Two things it never states are a bridge clearance and a fuel burn.
Air draft: no figure in the listing, and none in HMY's Powerboat Guide either. It doesn't matter much here. In the listing's photos she is a low express with a hardtop, and the tallest thing aboard is a radar dome on that hardtop. The Loop's one unavoidable fixed bridge is 19'6", and this boat is nowhere near it. A tape still earns its keep for route choices: the full Erie Canal runs at about 15 feet, and one call to the broker gets you the waterline-to-dome number. Water draft: the listing says 3.92 ft, which is 3'11". HMY publishes 3'9". Either number sits well inside the 5'0" line where the Trent-Severn starts asking for a waiver. Twin engines: yes, stated. Length: the listing says 37 ft. HMY publishes 37'1" for the hull and 39'8" with the pulpit. Marinas usually bill on overall length, so ask which number a slip will be quoted on. Our guide to which length a listing means covers this exact gap.
HMY describes the 3700 Open as a dual-purpose boat: family cruiser accommodations with a sportfishing cockpit. Below, that means a private stateroom forward, a large U-shaped dinette, a double-entry head and a galley. This listing describes the same layout, and the listing's photos show the queen up in the bow. So plan on one stateroom and one head. Guests sleep on the converted dinette, and everyone shares the head. The head is a good one, with a separate stall shower. The tanks set your rhythm: 98 gallons of water and 40 of holding decide how often you fill up and pump out. On an express, much of your daytime living space is the helm deck and cockpit, so sit under that helm enclosure and ask whether you'd spend a rainy week there.
HMY notes the 3700 Open came with several diesel choices, and names twin Caterpillar 3208s as one of them. This boat has the Cummins 6CTA option. 975 hours across roughly thirty years works out to about 33 hours a year, which is light use. Light use can mean long stretches of sitting, so the questions are how she was run and stored, and what the service records show. Our guide to high-hours boats covers the other end of the same question: the hour meter only means something once you know how the engine lived.
411 gallons is generous tankage for a 37-foot boat. Range is tankage times a measured burn at the speed you'll actually run, and neither the listing nor HMY gives a burn for the Cummins boats. Ask the owner for a logged figure at displacement speed and at cruise, or measure one on the sea trial.
Where the pending sale stands. The waterline-to-dome height. Which length the marina will bill. A logged fuel burn. How she was run and stored across those thirty years, and the service records on both engines and the generator. Then, with the boat in front of you, whether one stateroom and one head fit the way you'll live aboard.
It's not a verdict, and it's not a knock on anyone. We have never seen this vessel. She may be exactly the clean, well-kept boat her listing describes. Every question above is one a seller who knows the boat can answer in an afternoon.
Shopping a boat yourself? Send us the listing link at support@caniloop.net and it may become the next reader teardown.
Both opened and read on 2026-09-24: the Boat Trader listing (the boat's own advertisement, read with every section expanded; every "the listing says" above is its words), and HMY's Powerboat Guide entry for the 3700 Open (the model's layout, published specifications and engine options). Where the two disagree, we've shown both numbers rather than picking one.
If we've got something wrong, tell us and we'll fix it — support@caniloop.net. A correction from someone who has actually run it is worth more than anything we can write.