Many beaches in South Florida were closed after thousands of sharks were spotted of the coast as close as 60 feet away.  Lifeguards raised red flags getting people out of the water around 11am when the sharks were spotted but were allowed back in the water by the afternoon but warned to be careful. It was mix of blacktips and spinners that were migrating north after spending the winter in the warmer waters further south. March is the month sharks migrate north from Boca Raton to Deerfield Beach and north.