Beaches in the area - Exploring with a rental car

My husband and I are renting a car when we are in Negril this winter as we would like to go exploring. I was wondering if we are allowed to pull off the road and snorkel (or swim, or explore) at beaches along the highway/road anywhere in the vicinity (I would say within a two-three hour drive in either direction along the coast)?

I have been looking at google earth quite a bit and in some places see what looks like little dirt roads to the beach on uninhabited land. One place in particular I see is if you are heading west/south on A1 toward Negril from Green Island there is a resort called Rhodes. After the resort not too far are two dirt roads to the beach which almost look like they are attached (go in one way and go out the other). Is this private property? I do see that it is a national marine park, but we were hoping to visit without having to go through Rhodes.

Is most private property posted as well? We definitely don't want to trespass, but we love going exploring...

Anyways, if anyone has any ideas of little beaches to find that we can get to without having to pay a guide to take us, that would be grand!

Thanks everyone!

Bluefields has a public beach with parking lot, changing rooms/showers, food and beverage vendors. The last time we were there, we picked up some cold brews and headed down the beach. I got up to fetch another round and here comes the vendor with three more for us. I love the hospitality in Jamaica!