boatage

from The Century Dictionary.

• noun Carriage by boat, or the charge for carrying by boat.
• noun Boats collectively.
• noun The aggregate carrying capacity of the boats belonging to a ship.

from the GNU version of the Collaborative International Dictionary of English.

• noun Conveyance by boat; also, a charge for such conveyance.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The total capacity of boats, as of lifeboats on a ship.
• noun Conveyance by boat.
• noun A charge for transporting goods by boat.