This trampoline storage bag is designed to store loose items that you want to carry on your catamaran. The low profiles helps to eliminate line hang-ups. The bag is designed to attach between the hiking straps using line or shock cord. It features one compartment, 18 x 36 inches, with a zipper closure and a clear plasic map pocket. Constructed of tough Cordura fabric for years of service, but it's not waterproof. So put your electronic devices inside a waterproof pouch first.