The inlet runner 16 has a garvey hull form,which produces a boat that can get onto the plane quickly even with a big load aboard. designed primarily for construction. Build your own 21′ garvey flex boat with our downloadable plans. home; motor boats; 21′ garvey flex; purchase this downloadable 21′ garvey flex boat plan now for. Boat plans for a 18′ flats boat outboard garvey hull built in stitch and glue plywood..