Here's a chart to help you with size of bag needed and a link with more information and where you can purchase

http://www.walleyetacklestore.com/amoubebagsea.html

Size of Sea Anchor ** Length of Boat

15" Sea Anchor ** 16' - 19' boat

18" Sea Anchor ** 16' - 19' boat

22" Sea Anchor ** 14' - 24'boat

28" Sea Anchor ** 24' - 30' boat

36" Sea Anchor ** 28' - 32' boat

48" Sea Anchor ** Greater than 32' boat