Adrian Dann, from Lee-on-the-Solent, jumped into a liferaft as his vessel started taking on water two miles off St Catherine's Point on the Isle of Wight.
The 49-year-old alerted Solent Coastguard at 2.40pm yesterday before abandoning the fishing
boat and launching a red flare, which was spotted by the offshore patrol vessel Port Of Spain.
The Port Of Spain - designed by BAE systems for use in Trinidad and Tobago - was on trials at the time and launched a craft to pick up Mr Dann.
He was rescued from the liferaft and taken back to the Port of Spain as his 25ft boat sank. Mr Dann was dropped back at Gunwharf Quays where he was met by his wife last night.
Mr Dann, of Fieldhouse Drive, told The News: 'I went out for a routine fishing trip.
'I anchored the boat but a few minutes later the alarm for the bilge pumps sounded.
'I saw water coming through the vessel very quickly.
'I was in a state of shock so I called the coastguard to say that I was in trouble and I needed help.
'I'm ex-navy myself so I was quite surprised how frightened I was.
'It's really unnerving to see that volume of water coming in that quickly.
'I launched the liferaft because I was concerned about the stability of my boat - she was very unstable.'
Mr Dann said it was lucky the Port Of Spain was nearby at the time.
'I didn't realise that the vessel was so close,' he said.
'It's very fortunate the ship was in the vicinity.
'I'm very grateful to them.
'One of my old shipmates is one of the officers on board so he called my wife for me to inform her.
'I spoke to her afterwards and she was shocked as well.'
Mr Dann was uninjured but in shock after the incident.
However, a nice cup of tea did the trick.
'I was in shock and the team did a wonderful job in treating the shock.
'I now feel fine - after several cups of tea!
'The ship received my liferaft which was excellent but unfortunately my fishing boat sunk shortly after.'
Solent Coastguard watch manager Dave Williams praised Mr Dann for being well-equipped to deal with the sinking.
He said: 'This man helped to bring about his own speedy rescue by being well prepared for his trip.
'He had a VHF radio, the right kit including liferaft, emergency flares and he was able to give the coastguard an accurate position.'
>> Vote in our latest web poll.