Guernsey has won two silver medals in the watersports events at the 2011 Island Games.
Andrew Bridgman finished second in the Laser Radial Rig to secure the silver medal, while Johanna Asplund finished 12th.
Bridgman finished just ahead of Bermuda's Jason Saints in an event dominated by Mans Lundberg from Aland.
A lack of wind meant the sailboarding was decided by a single round with Sarnian Daniel Harradine taking silver.
It followed a number of failed attempts to windsurf through the week.
In the Laser Standard Rig Guernsey's Darragh Lee and David Aslett finished 13th and 14th respectively.