ANNA MARIA ISLAND, Fla. (WFLA) – A hammerhead shark gave one family quite the scare on Anna Maria Island on Memorial Day.

Corinne Lough says she and her family were enjoying the day when a hammerhead shark began to circle around their boat about 300 feet from shore.

Lough says she originally thought the shark was a dolphin. Hammerhead sharks can range in size from 13 to 20 ft. long. They weigh 500 to 1,000 lbs. and have a 20-to-30 year life span.