Though federal laws and rules don’t mention Hawaii’s fishing fleet by name, technicalities buried in immigration law, maritime regulations and agency rule books have combined to give it a rare distinction: In the Aloha State hundreds of foreign fishermen are stuck on their boats for years.

The Magnuson-Stevens and Jones acts make up the basis for most U.S. fishing laws. Their premise is that citizens should benefit from the work, food supply and revenue from American seafood. Boat owners, captains, and most of their crew are supposed to be American.

A rare exception , backed by Hawaii’s lawmakers, say noncitizens can be used only to catch “highly migratory species” and only outside of the exclusive economic zone. That narrows it down mostly to Hawaiian vessels catching swordfish and tuna.

And so the fishermen in Hawaii fall into legal purgatory.

Since the boats call the U.S. their home, the State Department’s Foreign Affairs Manual says the workers aren’t just foreign-based workers coming ashore for a break. If they were, they’d be eligible for a visa. Instead, they’re supposed to get immigrant visas, as if they were trying to move here.

That’s not happening under Customs and Border Protection, part of the Department of Homeland Security. Customs regional director Brian Humphrey said it’s “administratively cumbersome” with “no value added” to give them those immigrant visas. After all, the men are only here temporarily, with permanent homes abroad.

And so officials depend on another federal law that says boat owners are responsible for detaining foreign workers on board until they get visitor or immigration visas. Since those visas are not being issued, the fishermen remain captive in their place of work.