What Engines Were In PBR Boats?  | LakeWizard

Key Takeaways

  • The PBR Mark II boasted three machine guns.
  • PBRs have an all-fiberglass hull, making them lighter and more hydrodynamic.
  • The two engines in a PBR patrol boat were 180 horsepower Detroit Diesel 6V53Ns.
  • Instead of propellers, PBRs used a water pump and jet to provide thrust and turning.
  • Of the 718 PBRs that were made, roughly 36 are still around today.

Ever wondered what engines were used in PBR boats? Here's a little history of the boats and the engines that powered them.

PBR boats used two 180-horsepower Detroit Diesel (DDC) 6V53N engines. Diesel engines are better for shallow water, as they don't require a large cooling system or the high RPMs of gasoline engines. Their efficiency made them good for the conditions of a river delta.

With a passion for all things historical and mechanical, our goal is to provide you with the most accurate information possible from respected experts.

Table of contents


U.S. Naval History: An Overview of the Patrol Boat, River (PBR)

During the Vietnam war, small waterways winding through this Southeast Asian country served as a vital transport system for its locals.

Willis Slane and Jack Hargrave of renowned North Carolina-based boat-building firm Hatteras Yachts applied their expertise to craft the PBR vessel.

Adapting an existing fiberglass hull from the same manufacturer as a base model for design specifications proved crucial in creating timeless naval history with this river patrol boat.

What Is a PBR Boat?

This riverine boat, commonly referred to as the PBR, was a vital part of the US Navy’s brown water navy ops; it is a small patrol boat that was developed for the United States Navy’s River Patrol Force during the Vietnam War.

As part of their mission to control lines of communication during wartime, the U.S. Navy immediately deployed PBRs, fast-moving vessels equipped with machine guns used extensively throughout rivers and canals in order to patrol and secure them from hostile forces and attempt to disrupt weapons shipments as part of the Task Force.

These boats were indispensable in managing traffic along these waterways, which could be accessed by both friend and foe alike – ensuring that no one would go undetected when moving across Vietnamese waters.

They also kept shipping supply lines open, particularly via the Saigon River into Saigon, through Operation Game Warden and Task Force Clearwater, which aimed to deprive the VC of these waters.

Often, PBRs operated in pairs.

How Many People Were On PBRs? (Boat Captain and More)

Every PBR deployed during the Vietnam War was manned by a dedicated four-person crew consisting of a boat captain/patrol officer as leader and director, a helmsman for navigation duties, plus two gunners to maintain defense.

A First Class Petty Officer served as captain of this type of versatile boat.

Working together seamlessly in often challenging conditions with their lives on the line – these brave individuals formed an integral part of mission success.

What Weapons Did a PBR Boat Have?

These boats were equipped with twin .50 caliber light machine guns mounted on the front and single .50 plus an M79 grenade launcher for the aft gunner on the port and starboard sides.

Each gun was fitted with ceramic plating to provide armor against firefights with enemy soldiers on boats.

Specs and Dimensions

Mark I

Length: 31 ft

Beam (Width): 10.5 ft

Draft (Min. Depth): 2ft

Mark II

  • Length: 32 ft
  • Beam (Width): 11.5
  • Draft (Min. Depth): 2ft

PBR Boat Engines and Water Jets

PBR boats used two Detroit Diesel 6V53N engines coupled with Jacuzzi Brothers water jet pumps for enhanced thrust and steering capabilities. The complete lack of hull protrusions was one of this craft's great strengths.

The innovative PBR Patrol Boat River lacked a traditional propeller-driven propulsion system seen on previous naval ships.

How Fast Could a PBR Boat Go?

A Patrol boat riverine had a max speed of around 28.5 knots (32.8 mph).

Since these watercraft were built for riverine operations and riverine training operations and missions, agility, and speed were the top priorities. A boat with less speed and maneuverability would never be able to catch up to, let alone intercept, enemy crafts.

Who Used PBR Boats?

There were a few countries that operated PBRs, including:

  • United States
  • South Vietnam
  • Khmer Republic
  • Kingdom of Laos
  • Thailand
  • Brazil
  • Panama
  • Iraq

Are There Any PBR Boats Left?

There are roughly 36 PBR boats left in the United States between museums and private collections. Of those, there are maybe 5 or 6 still fit for use.

718 PBRs were produced in total.

These boats have a certain charm to them, although they are no longer used as patrol vessels.

Who Made PBR Boats?

In 1965, Uniflite of Bellingham, Washington, was contracted by the Navy to build the first fleets of PBRs.

The distinguished Mark I model stood out due to its hull constructed entirely of the then cutting-edge material fiberglass, developed in the 1950s.

At 31 feet long, it marked the beginning of an entire fleet that would be used throughout multiple wars and military conflicts and eventually inspired future crafts.

PBRs were serviced at many of the Navy’s repair facilities. During the Vietnam War, Mare Island was one such place.

Mare Island had been a base and former training area during WWII.

What's the Difference Between PBR Boats and Swift Boats (PCF)?

Both the PBR boats and Swift Boats (Patrol Craft Fast, aka PCF) were used for riverine operations during the war.

While these two boats are similar, there are notable differences that make them distinct.

  1. Purpose: PBRs were made specifically for Vietnam River Patrol Force activities, whereas a PCF was more versatile. A Swift Boat could handle riverine missions, direct engagement, or coastal brown water navy patrols.
  2. Size: PBRs were much more maneuverable in the shallow waterways of South Vietnam due to their small size. PCFs were larger, contributing to their usefulness in open-water Pacific Ocean situations.

Navy PBR usage and river patrol boats overall went out of style after the Mark II and the war’s end.

Why Was a River Patrol Force Necessary in South Vietnam?

The use of PBRs was necessary because of the challenges posed by Vietnam's geography.

The country has a complex network of rivers, canals, and waterways that were a key avenue of enemy infiltration and transportation for supplies and troops.

Submarine operations were impossible, and no standard primary war boat could handle the maze of shallow, weed-choked rivers.

This required a new type of watercraft that could be used to patrol these waterways and search river traffic effectively, which the US Navy had not needed until then.

In the midst of a guerilla war, US forces found themselves in need of an agile vessel that could operate in shallow, weed-filled, narrow waterways.

These channels could be smaller than a few boat lengths.

To keep up with the demands of war, US forces required a highly agile vessel that could sail through shallow and tight waterways while providing enough firepower to support land troops.

The Vietnam War at a Glance

The Vietnam War was a conflict that took place in the mid-20th century and lasted from 1955 to 1975.

The war was fought between North Vietnam, a communist regime with Soviet and Chinese backing, and South Vietnam, which had backing from several western nations, including the US.

The US became involved in the conflict in the early 1960s with the goal of preventing the spread of communism in Southeast Asia.

Over the next several years, the US escalate its involvement in the conflict, eventually deploying over half a million troops to the region.

Despite the massive military might of the US and its allies, the conflict proved to be a difficult and elusive fight, as the Viet Cong and the North Vietnamese army used guerrilla tactics to evade US forces.

The US eventually pulled out of the conflict in the early 1970s, and the communist North Vietnamese forces eventually succeeded in reunifying the country under a single government.

The war had a profound impact on the US, with over 58,000 Americans losing their lives and many more being wounded.

The conflict also had a profound impact on the Vietnamese people, with an estimated 2 million Vietnamese civilians and military personnel losing their lives.