A floating boat trailer for use with an automatic latching device for securing a boat includes a frame constructed and arranged to accommodate floatation panels, a hinged linkage mechanism having a spring steel extension blade attached to the trailer tongue, a pneumatic cylinder operable from a control transmitter to effect movement of the hinged linkage and a keel guide roller mounted on a spring steel plate located ahead of the bunker rails to keep the boat centered on the trailer and direct the U-bolt into the automatic latching device. A receiver, two pneumatic solenoid valves mounted on the winch stand, and a hand-held transmitter to operate them. A sealed winch stand upright acts as an air system surge tank for a tongue-mounted air compressor or for a compressor located in a towing vehicle. A pair of air springs, mounted in the trailer suspension system, allows the wheels to be raised or lowered by applying or removing air pressure.