Private boat vs shared tour boat for day trip to islands

Hello! We are a family of 8 (6 adults and 2 children - 4&5yo) currently staying in Bocagrandre for a few days. We would like to take a day trip on a boat to the nearby islands. Interested in snorkeling and chilling on the beach. We do not have snorkeling gear.

We’re considering hiring a private boat with captain for the day vs getting on a bigger boat for a shared tour.

1. Any idea on how much these respective options would cost?

2. Any advice or recommendations on which company to use?

3. Which tour/island would you recommend?

Thanks in advance for your kind help.