Leon Mansi -  The Legendary Pioneer of the Special Boat Teams (SBTs) 

LCDR Leon Mansi was born in Galveston Texas in 1928. He joined the Navy on February 5, 1944 as an enlisted man. He was rated as an Engineman and later Diver 1st class. Prior to his commissioning in 1960 he got hands on experience on engines, repair and salvage diving on ships and Small craft. Over these years he served on 9 separate ships. 

Mansi would deploy to Korea during that conflict in a Task Unit in direct support of combat operations.

In 1960 Leon Mansi was commissioned a Limited Duty Officer (LDO) in Engineering.

His tour of duty as an Officer was on an Amphibious ship where he earned the reputation of being an expert in Assault Landing Craft maintenance and operations. His second tour of duty was at Assault Craft Unit One at NAB Coronado and played a key role developing plans for testing and evaluating a Navy prototype craft, the Assault Landing Craft. The LCAX1.

However in world events in 1962 a counter insurgency against the spread of Communism grew in importance and in Vietnam the civil war would bring Mansi to Naval Special Warfare (NSW).

In 1962 the US Navy SEALs were created as a counter insurgency team with Sea, Air and Land as their concept of Operations and Mobility. The SEALs were parachutist which covered the air. They were small unit masters in Land Warfare. They had submarines for stealthy inserts and extractions and amphibious craft for beach operations.

A request from Vietnam deployed SEALs showed a weak link and they needed a Combatant Craft for direct close-in support in SEAL operations. Looking back on history they saw what was needed was the PT Boat.

At the same time NSW operations in Vietnam began under the Military Assistance Command, Vietnam - Studies and Observation Group (MACVSOG) in1962.

SEALs began deploying to DaNang training their South Vietnamese counterparts in NSW for raids against North Vietnam. SEAL support craft in those early years were indigenous craft (junks) of the area and two CIA owned Swift Boats.  They found this lacking because they needed a Fast Long Range Combatant Craft. MACVSOG and the SEALs asked for PT Boats. The Navy scrambled looking for a suitable combatant craft. The first were two 1950s experimental gasoline powered PT Boats. They were accepted and designated PTF-1 and 2. However, more were needed. The Navy found the craft that was ideally suited was Norway's Tjeld Torpedo Boats. The Navy immediately bought two designating them PTF-3 and 4. 

It was in 1963 crews were needed to man the PTFs. It’s here where Leon Mansi was recruited because of his extensive experience in Naval Special Warfare. One hundred twenty Navy Officers and enlisted men were chosen from their military records and sent to a Boat Unit with no name under classified orders. Starting from scratch Leon and the others put together the unit and trained PTF crewmen with Leon as its maintenance officer.

In Viet Nam MAVCSOG and the SEALs were needing the PTF so Leon was designated OIC (Officer in Charge) of Mobile Support Team ONE (MST-1) and first to be deployed to Vietnam. This would be the first of seven deployments to South East Asia for him.

Capt. Norm Olsen, SEAL, retired, recalls "In December 1963 three men from BSU-1, LTJG Lee Mansi, BMC Armstrong and SK1 Wilkins were sent to DaNang reporting to MACVSOG. Their duty as an advanced party was to set up a base that met the requirements for the PTFs and Crews. This base would be known as Camp Tien Sha and divided into two parts Upper base camp for the South Vietnamese Boat Crews called the Coastal Security Service (CCS) and Lower base camp for the PTF crews.

MAVSOG designated these Maritime Operations as SOG-34 Alpha. In just three months of hard work by Leon they were ready when in February, 1964 Lt. Burt Knight arrived with 20 sailors. Between late February and March they saw PTF-1 thru 4 arrive with the crews.

MST-1 was complete. At the same time in February, Boat Support Unit One (BSU-1) was established as part of Naval Special Warfare. Lt. Burt Knight would be its first Commanding Officer. Besides the PTFs, MST-1 took over control of the CIA Swift Boats. Leon was pushing the men hard working 12 or more hours a day and doing the same himself.

Jim Thomas a BSU-1, MST-1 plank owner and one of the first sailors in DaNang sent this e-mail: "While Lee was at MST-1 and BSU-1 he welded the Guys into a well trained Team. All rates worked together to meet commitments, turning Boats around to take on another mission. He insured that the Spare Engines, Parts and Equipment we need were there as well. Lee was a Tough Officer, but Fair and he knew his stuff. He worked us hard because the work needed to be done. Those sailors that complained or slacked off were sent back to the Fleet. But I liked Lee."

Lee was directly responsible for setting up the PTF Base in DaNang and by the time he left in October, 7 PTFs, 2 PCFs, and Fishing Junk Boats were under MST-1. Lee returned to Coronado BSU-1, but he also had a hand in setting up of the Mobile Repair Detachment in Subic Bay P.I. The Subic detachment would be the forward overhaul and repair facility for the PTFs and their giant Napier Deltic engines. 

Leon Mansi's direct influence with the CIA owned Swift Boats caused the US Navy in 1965 to buy the PCF Swift Boats for the Vietnam War. Boat Support Unit - ONE trained the first PCF Crews from March to October 1965. Lee would return again to DaNang to continue to improve the PTF servicing facilities. The Navy was now calling OPs 34-alpha the Naval Advisory Detachment (NAD). Regardless of what name it was called it was Leon Mansi's creation and he would return again and again to continue to improve DaNang’s Spec Boats efficiency.

BSU-1 crewman, Bill Moreo sent this e-mail: "My First contact with Lee was in 1965. He interviewed me to be part of the training crew for the PCF Swift Boats. He was one of the Good Officers. He was instrumental in sending me to French language school with Lt. Kruga prior to deploying to the Spook Base (DaNang). There I was assigned to train the South Vietnamese PTF Crews called the CSS and I was able to converse with the Vietnamese in French.

BSU-1 officer, Lt. Tom Gorla sent this e-mail: “I served with Lee in 1966 in Coronado and DaNang. We were not always together because of rotations in deployments, but I always remember him as the "Go to Guy" in engineering and training. He was highly respected and important player in the Unit.”

In 1966 the Vietnam War was growing bigger and bigger and the Navy was more involved with moving into Coastal waters and up Rivers. It was the largest Navy Involvement in combat operations on Rivers since the American Civil War. 

Navy SEALs deployed to the rivers without its organic boat support and were made to use PBRs. they even built and drove their own boats out of existing landing craft. Leon Mansi was critical in creating the specialized Riverine SEAL Support Craft under "Project Zulu''. These were interim (temporary) craft designated HSSC (Heavy SEAL Support Craft) based on the MK-6 Landing craft and the MSSC (Medium SEAL Support Craft) was based on the LCPL MK-V l. They were modified for riverine SEAL support at BSU-1 and for training the boat crews for these boats. In 1967 these craft would deploy in detachments to the SEAL Platoons and called MST-2 and MST-3.

Lt. John Woody BSU-1 recalls: "Lee was the Engineering Department Head at BSU-1 when I reported aboard. From gasoline engine PTFs to LCSRs, PCFs and even PBRs and the NSW Riverine Craft, Lee had a hand in the development of these boats".

Leon was also instrumental in developing the requirements for the LSSC (Light SEAL Support Craft), the MSSC that would eventually replace the interim MSSC. His reputation as the boat expert was well established and everyone knew it.

Leon regretted moving on from BSU-1 to his next command but he was ideally suited for the task. Leon Mansi's new duty station from 1967 to 1968 was River Patrol Flotilla 5 in Vietnam. He was part of Operation Gamewardens, TF-116 as the maintenance and repair officer for the flotilla and would serve for 14 months. RivFlot 5 had approximately 220 PBRs (Patrol Boat River) under its command. Its many divisions had 10 PBRs to a Division and were spread all over the Mekong Delta. This was an awesome responsibility making sure the PBRs were operational and battle damaged boats repaired. Leon while not his job, to better understand the PBRs, qualified as a Patrol Officer and went on Combat Patrols. This knowledge would aid him in his duties and growth as a professional Expert in Combatant Craft and the crews that manned them.

Upon completion of this tour in Vietnam, Leon returned to Coronado NAB where his duty assignment became Naval Operations Support Group (NOSG), aka, Naval Special Warfare Group Pacific and currently named Naval Special Warfare Group ONE. This was the headquarters Group for west coast Naval Special Warfare. Leon would serve as the Research and Development Officer for Combatant Craft. This staff job allowed Leon to put his brilliance about Fighting Boats on paper and allowed him to pass on his expertise and vision for future combatant craft.

Leon Mansi's last duty station was again with Naval Special Warfare. He returned to command Boat Support Unit ONE from 3 October 1969 to 26 August 1970. This would be the peak of Leon Mansi's career. He had put BSU-1 into commission and now returned to Command the Unit. It was rare in those days to see a LDO Officer command a Unit which only reflects the trust and respect NSW had in Leon Mansi. During 1969-1970 BSU-1's mission continued in Vietnam deploying detachments to MST-1 in Da Nang and MST-2 in the Mekong Delta which were by now using the LSSC, MSSC and still the HSSC. The interim MSSC was finally retired in 1969.

In Coronado BSU-1 continued with local operations of combat swimmer support and simulated missile boat attacks on the Fleet called Komar Exercises. Also Training and working up Detachments for deployments.  BSU-1 made sure the Subic Bay Repair teams was being well funded and well supplied with engines and essential parts for PTF overhaul. Also getting the Mobile Repair Teams (MRT) in Vietnam to support the MST-2 Combatant Craft. Leon Mansi as C.O. made sure all NSW requirements of his command were being professionally performed.

An e-mail from Tom Moffatt in-between his multiple deployments to MST-2 in Vietnam remembers Leon: "Lee was a Great Officer, tough, his bark was worse than his bite. Sailors being what we were did pull some pranks and shenanigans, and the C.O. (Leon Mansi) would threaten to bust me but never did, and he often said "I know you guys are up to something and I'll get you yet"! But Leon also went out of his way to personally talk one on one with his men trying to get them to re-enlist. As C.O. he was also known to test his own watch standers on the Piers and Gate security guards, according to BSU-1 Bob Stoner at morning or night.

Mansi turned his command over to Lt. Cmdr. R.C Jenson 26 August, 1970 and retired after a stellar career 30 August 1970. He had firmly established in Naval Special Warfare a Combatant Craft Unit from prior to commission to an existing unit today with the same Mission, SEAL Support with combant craft. The name of BSU-1 has changed since Leon was there. In 1971 it became Coastal River Division - 12. In 1978 it became Special Boat Unit-12. And in 2002 changed to its current name as Special Boat Team - 12.  There have been 22 continuous Commanding Officers since Leon Mansi commanded BSU-1. The old BSU-1 buildings are gone now, the piers that tied up the PTFs the LCSRs the MSSC and LSSC now have the most modern NSW Combatant Craft available.

Leon's legacy has grown fruit within NSW with more Special Boat Teams on the East Coast as SBT-20, and in Mississippi as SBT-22 and their crewmen are all professionals now called SWCC. They can now make a full career out of being a Naval Special Warfare Combatant Crewman.

After Leaving the Navy, Leon would work at many jobs and consulting work based on his naval experience. Many of these contracts would benefit Naval Special Warfare.

On July 11, 2002 Leon was awarded the United States Special Operations Command Medal.

In Oct 2014 the Combatant Craft Crewman Association (CCCA) and Naval Special Warfare celebrated its 50 years of NSW Surface Warfare Mobility Forces, the new term for the Boat units.  Leon Mansi was a honored guest and it was only fitting that he, the most Senior Boatguy cut the 50th Anniversary Cake with the Youngest SWCC guy. Many old BSU-1 vets enjoyed talking with "Lee".  Tom Moffatt kidded Lee, "You Never did Bust me."

The Legendary Boatguy Leon Mansi died Jan 30 2016.

  •  Thank you Leon Mansi for your service to Your Country

  • For the NAVY

  • For Naval Special Warfare                                                    

  • For the SWCC of the Special Boat Teams

From a February 19, 2016 memorial presentation by Jim Gray, MCPO Ret. Boatguy, CCCA Historian at the Coronado Amphibious Base.