Tallguy put this best so I’m going to quote him
“If you’re sitting in a zodiac with nothing but light shoulder weapons & pistols, and you get surrounded by patrol boats mounting heavy machine guns, the prudent thing to do is surrender or call on the support of your frigate. Since no help was forthcoming they did the only thing they could do — remember they couldn’t really inflict any casualties on the Iranians in the process (you can’t argue with Ma Deuce).”
What do you think they should have done? Swam for shore?
It was daylight. The Iranian vessels came from Iranian water, 2 miles away. They weren’t “suddenly surrounded”.
There was a journalist on board the ship, Ian Pannell, who said that they had just “boarded a dhow, a traditional Arabian sailing vessel, ... While they were on board, a number of Iranian boats approached the waters in which they were operating – the Royal Navy are insistent that they were operating in Iraqi waters and not Iranian waters – and essentially captured the Royal Navy and Royal Marine personnel at gunpoint.” (Scotsman)
http://righttruth.typepad.com/right_truth/2007/03/iranians_captur.html
Then, there’s the whole matter of the Cornwall watching, with radio contact with them......they could have easily made a stand on the vessel they had boarded, for long enough for help to arrive