That will depend on the operator. Some operators will have a boat for divers and another one for snorklers, some will put them on 1 boat. Just make sure that there is an adult from your party as well as a snorkle guide available. As far as the resort course, I believe that Padi recently made a change and from what I understand, if you take a resort course it is good for somewhere between 3 and 30 days( can't remember which) but it is now not a 1 day thing anymore. A middle ground option may be going on a snuba tour which is a mix between diving and snorkleing. I am not positive but I think most places will let an 8yr old do that.