RedactedNarrative: On 05/24/2017 at approximately 8 pm, operator along with 3 passengers, was sailing his vessel "Casa Del Playa" USCG Doc 1105249 on Lake Pontchartrain when his Jib Sail broke. Operator contacted Sea Tow New Orleans to request assistance.  Seatow advised him to drop an anchor to prevent drifting.  Operator deployed his anchor, which did not hold, and he continued drifting in a southerly direction. Around 9 p.m. the vessel struck the seawall on the southern side of Lake Pontchartrain near Lakeshore Blvd and subsequently sunk. All 4 persons on board were wearing PFDs. Alcohol and drug use is not suspected. The vessel was equipped with remote steering . The type of incident: 1)collision with a fixed object, 2) sinking. Contributing factors are: 1)fault of equipment, 2)Operator Inexperience, 3)Fault of Hull.