River Pageant organisers will announce later today which vessels will carry members of the royal family during the Diamond Jubilee extravaganza on June 3.
Also set to be revealed are the best vantage points and the other vessels taking part along the 7.5-mile route.
Boats and ships from across the world have begun their journeys to London for the River Thames pageant, including the Southampton-based tall-ship Tenacious .
The 200ft square-rigger is one of only two ships in the world designed to allow able-bodied and disabled crew members to sail alongside each other.
Tenacious, built by the Jubilee Sailing Trust , has just arrived back in Southampton after a 3,000-mile cross Atlantic voyage.
On board as she departed Jersey on her final leg, Captain Barbara Campbell told Sky News: "People who are blind or deaf or amputees don't see themselves as disabled and on here they are not.
"They can join in with everyone else because we have the facilities to allow them to do that. It's really inspiring to see what everyone can achieve."
The 714-ton Tenacious operates a 'buddy' system which pairs abled and physically disabled crew together and there are cabins designed for wheelchair users on board.
"We all seek adventure with an element of risk and this environment has both", on board medical purser Carol Redgrave explained.
"So someone who has had a disability for a long time may have been wrapped up by society in cotton wool and told, "You can't do this and you can't do that", but here that's all gone, everyone is equal."
Emma Simpson suffers from epilepsy - a three-week trip at sea would normally be prohibitively expensive for insurance reasons but on board Tenacious there is little she is not able to do."
"If I tried to do this anywhere else the insurance would be huge. This is the one place where I know no one will make a fuss. I just said, 'I've got epilepsy' and they said, 'Ok that's not a problem.'"
The transatlantic voyage has also given the crew the chance to get Tenacious ship shape for the Queen's river pageant.
"We've done quite a lot of work varnishing and painting across the Atlantic and she'll look great when she's part of the Diamond Jubilee pageant ," ship's mate Ali Travis explained.
"It's a great opportunity for the ship and we're all looking forward to it."
As her name suggest, Tenacious is set on her course for the Thames and Tower Bridge on June 3.
:: Read more about the Jubilee Sailing Trust at www.jst.org.uk or on Twitter at @JubileeSailing