RedactedNarrative: During rough seas, high winds and poor visibility, V1 was launched from Quay Boat Ramp. After taking on significant water during launch, the single occupant operated the vessel around the flat. Nearing the flat, the operator backed up V1 to avoid grounding and subsequently took on more water. V1 began to list due to being swamped. V1 capsized forcing the operator to jump overboard and swim to shore.