I spend winters in Sarasota and Siesta Beach has not been a very good producer for me. It is one of the more heavily hunted beaches in Florida. There are sometimes fresh drops but if you are not there early, there are others that will get them first. Parking is always an issue as the parking lot gets filled quickly. If you are not there before 10 am, you will be doing the siesta key cruise which is driving around looking for a spot to park. You will probably see several folks with detectors hunting on any given day. I hear they are going to be doing some construction on the beach area so there will probably be less available parking for a while.
The water is fairly even with a smooth gradual drop. The waves depend on the wind and so if the wind is right, you will get some fairly large waves but they are nothing compared to the waves on the East coast of Florida like Daytona. The waves there can get pretty big and hit you like a ton of bricks.
The beach is fairly busy on most days and so detecting can be tough with all those people around. I found getting there early, like and hour before the low tide is the best for hunting the wet sand. The white sand at night is amazing as it reflects any light and makes walking on the beach at night easy. I hunted the beach mostly at night and then the water during the day. I've only found a few rings there in the last couple of years. It is a fairly large beach so there is a lot of areas that are not used as heavily as the area in front of the beach house by the main parking lot.
The volleyball courts are hit very hard by detectorists just about every day. Anything dropped is usually found within hours there. Best to hit the towel line just before sunset and the low tide wet sand when that happens which is usually twice a day. Check the tide tables and plan accordingly.
