It's a rare international situation that doesn't give slick businessmen the chance to make a buck.

The crises over Iran and Afghanistan, with the resulting decision to beef up the United States' rapid deployment capability in the Middle East, have opened up profitable possibilities for American shipowners. They're trying to unload ships they can't use on the Navy -- at a cost to the taxpayers of hundreds of millions of dollars.

There's no doubt about the Navy's serious lack of transport ships to ferry troops and supplies to international hot spots. In an emergency requiring quick transportation by sea, the Navy would have to rely on a reserve fleet that consists of hulks dating back to World War II.

So some shipowners are trying to fob off uneconomical vessels on the Pentagon -- at outrageously high prices. With heavy lobbying and some legislative sleight of hand, they're about to convert otherwise useless merchandise into a profitable item.

One example: Sealand Industries has eight speedy oil-burning ships the company bought before the price of crude oil went sky-high. They are now no longer profitable to operate commercially, so Sealand is selling them to the Navy.

Sealand's ships are the fastest transports in the water, and the asking price of $35 million apiece is much less than they could be built for today. But they're not what the Navy wants, and it would cost an estimated $60 million to bring them up to scratch.

Insiders told my associate Peter Grant that a little tough bargaining might get the ships for as little as $18 million each. But both the Senate and House Armed Services committees have okayed paying Sealand its asking price.

An even more blatant money grab in the sacred name of national security is being attempted by Waterman Steamship Corp. The company ordered three cargo ships from Sun Ship Inc., primarily for trade with the Soviet Union. c

After Afghanistan and President Carter's trade embargo, the Soviet trade evaporated and Waterman found itself stuck with three ships for which there would be little use. The company's solution was to dump the three ships on the Navy -- for $270 million.

The Marine Corps, which would be the primary user of the ships, has shown little enthusiasm. The Marines wanted to wait for the TAK-X, a more versatile ship that's still on the drawing board.

But Sun-Waterman lobbyists deployed rapidly on Capitol Hill -- enlisting the aid of Rep. John Murtha (D-Pa.) -- and got the purchase legislation for their seagoing turkeys through a key subcommittee. The Pentagon's request for $207 million to produce the TAK-X the Marines wanted was shelved in secret session. In its place, sources say, the subcommittee approved $270 million for ships the companies are trying to dump.