- Yes
- No
TL;DR:
Coastal vessel, asymmetrical patrol boat with the Cyclone’s armament.
Overview:
A development of the Patrol Boat Mk.III, the Mark IV patrol boats were ordered in 1984 for the Panama Canal defence service. They were slightly enlarged compared to the Mk.III, being 3 feet longer in order to fit more powerful diesel engines to provide more power for the weaponry. They were the first new boats to be equipped with the now standard US Navy light weapon, the 25mm Bushmaster chain gun, which would also arm the Cyclone-class and Mark VI Patrol Boat. Service showed that earlier trials and concerns that the Bushmaster would corrode when exposed to saltwater were unfounded. They were painted dark grey which makes them easy to distinguish from the Mk.III boats in photos.
Only 3 Mark IVs were built, numbered 68PB841, 68PB842, and 68PB843, which were completed in 1985 and joined Special Boat Unit 26 at Naval Station Rodman in Panama. They participated in training exercises and patrols, and were transferred to Panama disarmed after the closure of Naval Station Rodman in 1999. One, Bocas del Toros, still remains in service with Panama.
Specifications:
Armament:
2x1 40mm Mk.19 AGL
2x1 25mm Mk.38
1x1 Mk.2 mortar combined with 1x1 12.7mm M2Displacement:
46 tons fullLength: 20.7m
Beam: 5.5m
Draft: 1.2m
Propulsion: 3 GM 12V-71T1 diesel engines, 1950 hp, driving 3 shafts
Speed: 26.7 knots (49.4 km/h)
Range: unknown
Crew: 7
Systems:
Furuno 1411 navigation radar
Images:
Sources:
Friedman, N. (1987). Post-Vietnam Small Combatants. In U.S. Small Combatants: Including PT-Boats, Subchasers, and the Brown-Water Navy: An Illustrated Design History (pp. 408–411). Naval Institute Press.
Saunders, S., & Philpott, T. (2015). Panama. In Jane’s Fighting Ships 2015-2016 (p. 618). IHS.
https://www.warboats.org/mkiv.htm
https://www.warboats.org/SBU12.htm
https://www.warboats.org/SBU26.htm
https://www.navypedia.org/ships/usa/us_cf_pbiv.htm
Images:
https://www.ebay.com/itm/374814986144