From Elemental Lords of Porphyra

Silica Dory
Aura moderate transmutation; CL 7th; Weight 4 lbs.
Slot none; Price 7,200 gp
In its unactivated form, a silica dory looks like a squarish, well-made glass bottle. When the proper command word is given, the bottle expands in the space of a single round to form a boat 10 feet long, 4 feet wide, and 2 feet in depth. It now contains a pair basket-spikes (to push across glass or sand) a mast, and a lateen sail. The dory can travel like a boat across sand (or ash) and surfaces of glass or similar substances. It will sink like a stone in water. All of the basic principles of boating apply to the dory, but with the substances indicated. A second command word causes the dory to fold itself into a bottle again, but only when it is unoccupied.
Requirements Craft Wondrous Item, fabricate, creator must have 2 ranks in Craft (glass) skill; Cost 3,600 gp