An efficient double-ended watercraft is disclosed that comprises four
low-Froude number hulls: two forward, two aft, two on the port side, and
two on the starboard. Each hull comprises an independent engine that
drives a propeller shaft and propeller that is located amidships. The
propeller shafts on the starboard are collinear, as are the propeller
shafts on the port. The propellers on the starboard are near each other
and counter rotate, as do the propellers on the port. The propellers are
variable-pitch propellers. When the ferry is changes from moving forward
to moving in reverse and from reverse to forward, the propellers on the
starboard exchange pitch. This enables the ferry to move as efficiently
in reverse as it does when forward. The propellers on the port also
exchange pitch when changing from moving forward to moving in reverse and
from reverse to forward.