Blue Islands are giving winning 'pilots' and runners up flights from the island to Southampton as prizes.
The aim of the competition is to create the aeroplane that travels the furthest from Crown Pier.
The judges will only accept entries from those using some form of flying contraption, vehicle or similar craft to attempt their flight - the only restrictions are the craft can only be powered by muscle, gravity and imagination.
Blue Islands managing director, Rob Veron said: "The Blue Islands Man Powered Flight will be an exciting event this year with the opportunity to win lots of flights to Southampton with Blue Islands.
"As a local company we are keen to support such community initiatives and help ensure the longevity of this fundraising family event, which the Guernsey Round Table has organised so expertly over the years.
"The more people who enter, the more funds will go to this year’s main beneficiary: The Guernsey Sports Commission’s Street Sports programme. We look forward to seeing all of the entries on the day!"
Mike Ozanne of the Guernsey Round Table said,"Both we, as the organisers, and RBC Wealth Management, as sponsors of Harbour Carnival for the last six years, are delighted with these generous prizes from local airline Blue Islands, one of our islands’ well known brands.
"We very much welcome their enthusiasm for the event, and it will be interesting to see all the creatively designed ‘aircraft’ take to the skies, and waters, again this year."
Prizes are awarded for the longest distance and the best craft.
Entries to the event can be made on the day so there is plenty of time to create a man powered
The Blue Islands Man Powered Flight will take place at 9pm on August 29th at the Crown Pier.