On masted ships there are many ropes and pulleys designed to facilitate the operation of the sails, secure objects down, and to tie off the ship when docking. Typically such ropes are coiled near the sides of the vessel, tied off against the mast, or attached to the bow or stern of the ship. Canny sailors can use their rope use skill in order to do some tricky things onboard ships with these ropes and pulleys that happen to be around.

Grabbing A Rope
As a move action or as part of a move action, anyone can grab one of these ropes. It is up to the GM's discretion whether a rope is available or not, but typically they will be found adjacent to the sides of the ship, adjacent to the mast or masts, and perhaps at the extreme bow and extreme stern. Although a fate point might change a GM's mind, the GM has final say over where ropes are located on board ships. A character must have at least one hand free to grab a rope. Grabbing a rope provokes an attack of opportunity.

Shiver Me Timbers
As a move action, a character who holds one of these ropes may use it to make a unique move on the ship by swinging from the rope attached to the masthead while loosening a rope holding back a counterweighing sails. Such a move requires a rope use skill check depending on what kind of move that needs to be done. A pirate character may add his pirate levels to this roll as well. Leaving the 5' space where the rope was picked up forces the rope user to drop the rope.

Use a rope to swing from the rail of one ship to just inside the rail of an adjacent ship (5)
Use a rope to swing up to half the mast's height in a straight line (5)
Use a rope to lift and swing up to half the mast's height landing on board the same ship (10)
Use a rope to lift the mover to the crow's nest of the nearest mast (10)
Use a rope to lift and swing up to half the mast's height landing on board an adjacent ship (15)
Use a rope to lift and swing up to the mast's height landing on board the same ship (20)
Use a rope to lift and swing up to the mast's height landing on board an adjacent ship (20)

Moving by this method still draws attacks of opportunity as normal. It is considered that the mover is lifted 10' into the air, sideways a certain amount, and then dropped directly down onto the target square. Failure to make the required DC check could prevent any such movement or land the mover in another square entirely at the GM's discretion.

Blow The Man Down
As a standard action, a character who holds one of these ropes can try and grapple an adjacent opponent. The rope user makes a touch attack, drawing an attack of opportunity just like starting any other grapple, but instead of rollling an opposed grapple check (d20 + str + bab) the rope user opposes the other character with a (d20 + rope use + pirate level). A successful grapple does damage, or can be used to pin an opponent as a grapple normally does, but no other grapple options are available. Similarly, only the escape option is open to the grappled opponent. Only the opponent grappled by the rope user is considered to be grappled for the purposes of determining DC. The rope user is not considered to be in the grapple.

If a victim is pinned by the rope user in this way, they are considered helpless to the rope user for the purposes of coup de grace. Alternatively, the rope user can tie the rope off as another standard action leaving the pinned opponent considered tied up. The rope user rolls a rope use skill check which the pinned and tied character must then beat. The rope user does not get the usual +10 bonus since they are tying their victim up in such a hasty way.