SRD:Elixir of Swimming

Elixir of Swimming: This elixir bestows swimming ability. An almost imperceptible magic sheath surrounds the drinker, allowing him to glide through the water easily (+10 competence bonus on Swim checks for 1 hour).

Faint illusion; CL 2nd; Craft Wondrous Item, creator must have 5 ranks in the Swim skill; Price 250 gp.