Has anyone seen a bow thruster design on a pontoon boat ? The scheme would have a tube w/open ends, welded cross ways (right angle ) inside of the hull tube (s). A bi-directional motor fitted with a propellor is attached inside of the thruster tube. Water/air tite fittings are installed in the design for routing the motor conductors. A motor driven gate may be required to reduce parasitic drag, when the thrusters are not in use. Or, a water foil may be adequate.