The instinct says a boat built for the ocean can handle anything smaller. The Loop is where that instinct sends people shopping in the wrong direction.
A boat built to survive an ocean was shaped by the ocean's demands — deep draft for stability, high freeboard, mass. The Loop makes almost none of those demands and quietly punishes several of them. The question that actually sorts Loop boats isn't "how much boat?" It's "does this boat fit the specific doors the route runs through?"
An experienced Trawler Forum member, in a thread about expedition trawlers, named the error better than we ever have: "People often consider trawler features and capabilities as a cumulative stack: if it is built to withstand open ocean unpredictability, it can certainly handle anything of lower intensity… It doesn't work that way."
His example was a 65-foot expedition trawler on the ICW: technically able to run it, but "a frustrating experience bordering on white knuckling as you hope the charted 8' of water is accurate." The capability that crosses an ocean and the fit that enjoys a shallow, bridge-crossed, lock-stepped route are different axes. Points on one don't transfer to the other.
The same member put dimensions on it: a 70-foot displacement trawler carries its deep draft, its tall air draft and its wide beam usefully "in an open ocean" — and as limits and expense "for the other 99/100 days spent cruising at the edges of open ocean." And from his own delivery down the Pacific coast: "draft deeper than 5-ft will keep you out of some places you want to go. Deeper than 7-ft and it rules a lot of decision making - I can only liken it to trying to find restaurants where you can eat with two pet Great Danes."
On the Loop, each of those dimensions is a door that's either open or closed, and each has its own guide on this site with the controlling facts: water draft decides which routes and anchorages exist for you, air draft decides your bridges and whether a whole leg is even available, the locks put hard walls around the trip, and length decides slips, rafting and cost at every stop. A bigger boat doesn't pass more of those tests. It usually passes fewer.
Blue-water attributes earn their keep on crossing days, and the Loop essentially doesn't have any — it is marinas, anchorages, rivers, canals, locks and small towns, day after day. Choosing a boat for the Loop by its ocean pedigree is optimizing for the day the route doesn't contain and paying for it on all the days it does. The buyers who get this right work from their own requirements first — the trip they'll actually take, the doors it runs through — and let the boat follow. That ordering, mission first and boat second, was the one point of unanimous agreement among the experienced owners in that same thread.
None of this is a size cutoff, and we don't publish one. Boats of many sizes complete the Loop, larger ones among them, and their owners planned around the closed doors knowingly — deeper stops, timed tides, legs skipped by choice. The point isn't that a big boat can't go. It's that the trade-offs are knowable before you buy: which anchorages, which bridges, which legs your dimensions give up. Knowing that in advance is the difference between a chosen compromise and a discovered one.
It's not a verdict on any boat, and it argues nothing about seaworthiness — for a buyer who genuinely will cross oceans, the blue-water axis is the right one to shop on. We haven't run the ICW in a 65-footer; the member we quote has run boats most of us never will, and we've linked his words rather than borrowing them. What we hold is narrower: the Loop selects for fit, fit is measurable, and the measuring is worth doing while the boat is still a listing.
The cumulative-stack passage, the ICW-in-a-65-footer description, and the draft thresholds are one experienced member's posts in a public Trawler Forum thread (opened and quoted directly, 2026-09-03) — his figures stay his, attributed, never restated as ours. The controlling Loop numbers live in this site's own draft, air-draft, locks and length guides, linked above, so no fact has two homes.
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.