It will.
you get in the boat and sink
The key card is for later. Return to the museum, where you have a package waiting for you.
if you want keycard then go to poptropicahelp.net and do island guide
There is nothing to do with the key card immediately. Go back to the museum to find a package waiting for you. You will be leaving Counterfeit Island (temporarily) to travel to another island, for some valuable information.
its on the edge of the dock
When the strange man jumps in the boat he will drop it
The key card is used later in the game in the Black Widow's lair. Save the key card and return to the museum.
The key card is dropped at the end of the scooter chase. It is used much later in the game.
When he leaves he will leave it on the docks
a girl named paisley
The Black Widow key card is dropped by the art thief (shady guy) when he makes his escape by boat.