Triton's Conch
Item 9MagicalTransmutationSource Core Rulebook pg. 576 2.0Price 640 gp
Usage held in 1 hand;
Bulk L
If you put this large opalescent conch shell to your ear, you can hear the sound of the roaring sea crashing against the shore.
Activate 
Interact (
auditory);
Effect You can raise the conch to your lips and blow into it, letting out a long, rumbling note. For the next minute, you and all allies who were within 30 feet of you when you activated the conch gain a +2 item bonus to Athletics checks to Swim and can breathe under water.