Sea Traps are traps in Phantom Hourglass. They are barbed, double wires held in place by two sea urchins that infrequently surfaces upon the sea of the World of the Ocean King while Link is traveling. Although it is possible to attack the two urchins that bind the wires with the cannon, it is much easier to just boat-jump over them, in a similar way that Epona does in terms of horse jumping in Ocarina of Time and Twilight Princess, on solid ground. Since they're immobile, it's also an option to stop and change course to avoid them completely.
Sea Traps are the only enemies Linebeck directly explains how to defeat. Because of the explanation scene, a Sea Trap will always be the first sea-borne enemy Link encounters in Phantom Hourglass.
Sea Traps are the only enemies which can be completely avoided by boat-jumping in Phantom Hourglass.
Names in Other Regions
↑"Hey, see that weird thing that just surfaced, Link? It's called a Sea Trap, and we're headed right for it!" — Linebeck (Phantom Hourglass)
↑"One of those weird things we call a Sea Trap just emerged, Link! We're on a collision course! So, two options! Blast each end...or jump the thing! Time it right and tap the Jump Arrow at the bottom of the screen to leap!" — Linebeck (Phantom Hourglass)