Various embodiments of storage devices for a boat are provided. One embodiment is a storage device for removably attaching to a t-top on a boat and for storing items. One such storage device comprises: a frame comprising marine fabric having an opening to a storage area defined by the frame for receiving an item; an access flap for enabling a user to access the storage area, the access flap comprising marine fabric attached to a top portion of the frame and extending over the opening to a bottom portion of the frame for securing the access flap to the bottom portion of the frame; and a plurality of straps attached to the bottom portion of the frame for providing support from underneath the frame when it is attached to a t-top on a boat, each of the plurality of straps having a first end for attaching to a first horizontal structure of the t-top and a second end for attaching to a second horizontal structure of the t-top.