Several options, that are not the public ferry out of Marigot:

Calypso Charters: 264 584-8504

Link: 264 497-3290 / 772-4901/ 582-9163

Gotcha: 264 476-1428 / 235-7902

Funtime: 264 476-8106 / 264-497-6511 / 264-235-7022

G.B Ferries: 264 235-6205