Looks like they were diving in the inlet, around peanut island and the Munion Islands. I could see the smoke stacks from the power plant in a couple of shots (Peanut Island), the inlet pump house (Palm Beach Inlet) and the new condo next to mine (Munion Islands).
There is a deep hole in the lake on the South side of the island. It is deep, blue and water always swirls around it. I ran over something one day when I was out sailing by myself while crossing the hole.
My wife used to say she saw manatees near the shore between us and little Munion. I sailed there one day to prove her wrong and the water was only one foot with a few more feet of mud. Maybee it was the sea monster.