Antique White premium slub cotton sweatshirt with authentic 1960's Vietnam War US Navy Riverine design.

On December 18, 1965, for the first time since the American Civil War, the US Navy formalized its new, brown-water navy in Vietnam. Initially, the brown-water navy patrolled the inland waterways of the Mekong River, primarily with South Vietnamese river craft (RAG—River Assault Groups) boats, which were mostly inherited from the French Navy during the previous war. As the new fiberglass Patrol Boats, also known as PBRs or Mosquito Boats, using water jet propulsion became available, it became the main interdiction vessel for patrolling the Vietnamese Mekong River country and movement of Special Forces units as depicted in the Vietnam classic Apocalypse Now.

Riverine PBRs also provided US Navy SEALs the capability to operate in the shallow canals and massive rivers of Vietnam during their earliest deployments; serving as an insertion and extraction platform and providing direct fire support if needed.

In 1965 there were an estimated 80,000 Viet Cong and VC sympathizers in the Mekong Delta of South Vietnam. Of these some 30,000 were thought to be regular troops and 50,000 part-time guerrillas capable of operating in battalion-size units. The VC was the target of the SEALs. The task of recapturing the waterways was assigned to Task Force 116, code named Game Warden. Its original mission was to patrol inland waterway, enforce curfews, search river traffic, and deny the Vietcong an opportunity to infiltrate and re-supply.

The PBRs were replaced with boats specifically designed for SEAL operations. These were the Light SEAL Support Craft (LSSC) and Medium SEAL Support Craft (MSSC). Several were dedicated to each SEAL Platoon, and operated and maintained by the Boat Support Unit ONE Mobile Support Teams (MSTs)