The Help for Heroes gig H4H Valiant was built at the National Maritime Museum's dedicated workshop, supervised by boat builder Andrew Nancarrow.
The veterans left Sennen at 07:00 BST and completed the crossing to Tresco in eight hours and eight minutes.
The Great Big Cornish Gig Project was the brainchild of amputee Al Henderson.
The former Royal Marine, who was injured on a tour of duty in Afghanistan with 40 Commando in 2010, said the project had been a huge success.
"It's brilliant working with a great group of like-minded guys and people have got some good stuff out of it," he told BBC News.
"We've got people going on boat building courses and wood turning courses, so it's been a huge success,"
Describing the gig as "a gorgeous boat with a light and lovely glide", Mr Henderson said Valiant has been painted in Help for Heroes colours.
"You've got the Royal Air Force blue, then the Army red and the Royal Navy blue, then a strip of gold to simulate the medal on the badge," he said.
The gig will take part in the World Pilot Gig Championships on the Isles of Scilly at the end of the month.
Project manager Mike Selwood said the aim of the project was to open up new opportunities for wounded military personnel as well as showcasing the heritage behind Cornish gigs.
All modern Cornish pilot gigs are based on drawings of a boat built in 1838 by William Peters of St  Mawes. They must be made from Elm and be 32ft (9.8 m) long and 4ft 10in (1.5m).
A traditional Cornish pilot gig, built of Cornish elm and crewed by injured veterans, has rowed from Cornwall to the Isles of Scilly.