Coron is known for it's diving and underwater life. But I don't know about the snorkeling. It could have been that El Nido is usually good but we had some bad visibility, currents, etc that made my experience not as good as usual. The jellyfish weren't a big issue, and only on one beach area out of dozens.

But part of EN snorkeling is the views, the beaches, the lagoons you can only reach by swimming through a rock opening, the fresh fish lunch cooked under the palms and the crystal blue water. EN has all of that. Plus gorgeous sunsets. You can even get a local to take you to an island, camp and have it to yourself, and they'll come get you the next day. I would go to EN for sure, I'm not saying don't go. I'm just saying don't expect the snorkeling to be as good as maybe some other places for sea life/coral, depending on your experience.

Coron is easy to get to with direct flights from Manila on the budget carriers. It's hard, however, to get from El Nido, or the main part of Palawan, to Coron without going through Manila.

The best snorkeling I had in the Phils after quite a few tries was at Balicasag, coming from Bohol/Panglao, and also snorkeling with the whale sharks at Oslob. Although Oslob gets a lot of guff for the environmental/animal impact, and some people will not consider it, it was quite spectacular IMO to be that close to the whale sharks.