RedactedNarrative: V1 was engaged in offshore recreational fishing activities in the Gulf of Mexico. V1 began flooding by taking water over the transom. A combination of flooding and failure of the bilge pumps resulted in V1 capsizing, forcing the occupants into the water. 
  
  V1 was recovered and towed to Punta Rassa by Sea Tow. Officer met with Sea Tow at Punta Rassa to conduct an inspection of the vessel. Officer observed the swim platform was filled with water. The stern of the vessel sat low in the water even with salvage efforts of removing water from the bilge. They observed the bilge plug and swim platform plug intact. 
  
  On 9/29/14, Officer and I conducted an inspection of the vessel at Offshore Performance in Fort Myers. There were no obvious defects to the hull or through hull fittings which would have resulted in V1 taking on water. We were unable to determine if the swim platform was full of water prior to the flooding, however it is a possible contributing factor to V1 sitting low in the water allowing seas to come over the transom. Measurements of the swim platform were 45 inches length, 25 inches width and 14 inches depth. Based on the measurements the swim platform can hold an approximate 68 gallons of water(approximately 544 pounds). We also found a fresh water holding tank inside of the center console. The holding tank measured 24 inches length, 12 inches width and 17 inches depth which can hold 20 gallons of fresh water(approximately 160 pounds). 
  
  The mechanics inspection at Offshore Performance revealed the starboard side bilge pump was inoperable with a operable float switch. The port side bilge pump was operable with a inoperable float switch. 
  
  The weight of four adults and three children on the vessel, the possiblity of added weight of the swim platform being full of water, choppy sea conditions, and an inoperable bilge pump resulted in the flooding and capsizing of V1.