The United States Coast Guard Auxiliary was established by Congress in 1939 to assist the Coast Guard in promoting boating safety. It includes more than 30,000 members from all walks of life who receive special training so that they may be a functional part of Coast Guard Forces. Auxiliarists assist the Coast Guard in non-law  enforcement programs such as public education, vessel safety checks, safety patrols, search and rescue, maritime security and environmental protection and Coast Guard Academy introduction programs for youth. Auxiliarists volunteer more than 2 million hours annually to benefit other boaters and their families.

Flotilla 11-3 was established (as Flotilla 73) in 1951 as part of the U.S. Coast Guard Axiliary's District 7 under Division 7, part of the greater Tampa/St. Petersburg area. Flotilla 11-3, located in Madeira Beach, Florida just north of the John's Pass bridge.

A group of 16 to 20 boating enthusiasts meeting at Harry's Seafood Restaurant, Madeira Beach, FL formed the group. The organization was established to:

a) Promote boating safety through public education, vessel examinations, and boating area patrols.
b) Foster fellowship among our members.
In the early days, Public Boating Education classes were conducted at Harry's or the Madeira Beach City Hall in those days. Funds were raised for construction of a building in 1956. The building was completed in 1957, and is our present location. Since then all Flotilla activities, educational classes, meetings, and fellowship events, have been conducted in this building.

The Flotilla has always been involved in supporting the U.S. Coast Guard with their operations. In 1980, twenty three members received a "USCG Certificate of Operational Merit" for aiding CG activities at the sinking of U.S.C.G. cutter "Blackthorn" at the mouth of Tampa Bay. Five members went to Key West to aid the Coast Guard during the Cuban refugee "Sealift". Four vessels and sixteen crewmembers provided support to the C.G. at the site of the May 1980 collapse of the Sunshine Skyway Bridge.

Patrols may also involve Search and Rescue (SAR) missions. A patrol leaving John's pass in dense fog located a downed aircraft. In 1983, an "off-duty" auxiliarist performed a search mission to locate a lost sailboat in the Gulf.
Flotilla 11-3 patrol boats can also be found at local special events, such as holiday boat parades, the Gasparilla "invasion". We even went as far as sending boats over to Cape Canaveral one year for a Shuttle launch.
Division 11 is afiliated with Coast Guard Station Sand Key. It's Area of Operation now extends from Aripeka down to Treasure Island.

On April 6, 2009, the Flotilla was re-assigned to Division 11 as part of the U.S.C.G Auxiliary's "modernization" plan.