I bass fished in that lake for 30 years (30 years ago)and when they straightened the canal out it started causing problems. I forgot all the problems but one was the run off from the farm, citrus fields that ran into the canal/lake. They put locks in from Lake Kissimmee (6 I believe). When they drew down Lake Kissimmee you could drive a vehicle all over that lake and you could see all the deeper holes as well as the natural path of the Kissimmee River. It was something to see.
In 1970 i took a boat trip from Davis Island (tampa) to Fort Lauderdale via the big lake.
When we got to Palm City i was sitting on the cabin cruisers bow and yelled to the old man that we were about to run aground.
We were in17 feet of absolutely clear water.
Today i sail the Stuart area all the time and NEVER see clear anything.