PWC #1 OPERATOR WITH NIECE AS PASSENGER WAS FOLLOWING HER HUSBAND WHO HAD A NEPHEW AS PASSENGER ON PWC#2. BOTH PWC'S WERE HEADING NORTH IN SAME DIRECTION. PWC#2 SUDDENLY STOPPED WHEN HE PUT HIS PWC IN REVERSE (TO CREATE A SPRAY). THIS ACTION CAUSED PASSENGER (NEPHEW & OPERATOR TO FALL OFF) NEPHEW SUFFERED HEAD LACERATION FROM HITTING PWC#2 OPERATOR PFD. WHILE IN THE WATER, PWC#1 OPERATOR WAS CONVERSING WITH HER RIDER--NIECE WHEN THE NIECE SHOUTED 'THEY ARE DOWN'. PWC #1 OPERATOR THEN TRIED TO AVOID HUSBAND & NEPHEW BUT WAS UNABLE TO AVOID STRIKING HER HUSBAND AS HE WAS IN THE WATER DIRECTLY AHEAD. AFTER THE CONTACT WITH THE HUSBAND IN THE WATER, PWC #1 OPERATOR DID SUCH A QUICK TURN, THAT SHE & THE NIECE FELL OFF THEIR PWC. PWC#1 OPERATOR--WIFE SWAM TO HER HUSBAND WHO WAS UNCONSCIOUS IN THE WATER. SHE HELD HER HUSBAND'S HEAD OUT OF THE WATER WHILE OTHER WATERCRAFT & PEOPLE SHOWED UP TO ASSIST. INITIAL OFFICER REPORT WAS VERY INCOMPLETE. REPORT OMITTED WATERCRAFT & PERSONAL INFORMATION OF OPERATORS, RIDERS AND INJURIES. SUBSEQUENT OFFICER REPORT PROVIDED MOST OF THE PREVIOUSLY OMITTED INFORMATION. MORE DETAIL DESCRIPTION OF THE INCIDENT WAS PROVIDED BY PWC#1 OPERATOR (WIFE) VIA TELECOM IN NOVEMBER 2011. LATER CONVERSATION WITH PWC#2 OPERATOR - HUSBAND CONFIRMED HE INTENTIONALLY PLACED HIS PWC IN REVERSE WHICH CAUSED HIM & HIS NEPHEW TO FALL OFF PWC#2.