Boat tractors. Or tractor boats
At Abel Tasman Nat'l Park, along the far NW tip of the island, boats ferry tourists to different sites to enjoy hiking, sailing, kayaking, etc. However the very shallow mud flats and large tide variations mean that at certain times of day the boats are carried to the deeper water by tractors. Yep. Haven't lost too many of them, I hear. We boarded one of these boats on land while it was still on a trailer towed by the tractor.