Worth noting that under the latest taxonomy, given its geographical location (Florida's east coast) and estuary habitat, this is most likely a Tamenend's Bottle-nosed Dolphin, T. erebennus.
(healthy individuals of the oceanic form, from what I can see, have only been confirmed several kilometres from the coast, but would be interested if anyone knows better!)
If so, this would actually be an increase in the mammal count for this trip, as we also saw bottlenoses in Charlotte Harbour on the Gulf of Mexico coast, which are still considered as part of T. t. truncatus for now.