The PBR or 'Pibber' had a fibreglass hull and water jet drive allowing it to operate in shallow, weed choked rivers. The Mk II was longer than the Mk I at 32feet with an 11 foot 7inch beam. The Pibber operated with a crew of 4. It was powered by a 220hp Detroit Deisel 6V35N engine and was capable of a top speed of 28.5 knots (53km/h). The Pibber was armed with twin M2HB 0.50 calibre machine guns as well as a single rear 0.50 calibre and side mounted M60 7.62 MG and Mk19 grenade launcher.