Is there a cost to see the manitee

No cost, it's free 😊

This is a free park and the manatee are naturally occurring... If they're there and you're looking, you will see them. If not, nope, no manatees. Nature, not Sea World. There are no pens, nor are the animals hunted and placed in cages or pens -- Nature, a naturally occurring phenomenon.

Yes, there is also a trail to walk with an observation deck to look over the water

Yes $49.99 for 3 min

No its along the river

Good luck. The water is murky.