In February of '76 we were in the Miami-Nassau sailboat race when we spotted flares from another boat that was taking on water, somewhere SW of Great Isaac Light. A norther was blowing 20 - 25 kts, and seas were 10 ft. Our boat took five of the eleven crew members to our boat in a bow-to-stern transfer, and another vessel took the remaining six. The USCG flew out and dropped pumps, and then a cutter arrived to take the boat in tow. The crew was safe, but the floundering boat sank before getting back to port.