There really is not any snorkeling in front of any of the resorts.
Pirates Point would be the best option for that. It is the only resort not in the sound, so it has open ocean in front of it.
Assuming easy access is a must, the best snorkeling is at Point of Sand, but be careful of the tide. Next best snorkeling is on the north side in the marine park.
There are not any resorts at either location. All of the resorts are on the south side of the island.
The closest snorkeling on the south side is Preston Bay, which is a little bit west of Pirates Point. It can be shallow there at low tide.
There is not much of anything except grass in front of LCBR or Southern Cross.
Assuming you are capable of it, you can ride a bike to the north side and to Preston Bay, but Point of Sand is a hike, you can do it, but it is a hike. All the way at the east end of the island. It should take you at least 30 minutes, honestly likely more.
Hope that helps.