Xtabi provides some nice snorkeling right in front and either way up and down the cliffs. I've snorkeled the coast from there all the way to Canoe Bar and it's all good. The reef at Samsara in that stretch is fun too. Stay close to the cliff wall. Lots of interesting critters along the wall. Some big coral heads between Blue Cave Castle down past Home Sweet Home always have a few Lion Fish hanging out. A Lot less the past few years which is a good thing.
If LTU has their ladder down the coast from there to Catcha Falling Star is nice too. Be aware of the boat traffic at Rick's.
The bottom line...any place you can gain access to the Sea is pretty good snorkeling on the West End cliffs. Buy a drink of two, maybe lunch and it will open up the ladders to adventure.
