What is better at burning calories, swimming with a snorkel or regular swimming?

For the most part, these answers are wrong. With respect to calorie burning, there is NO difference. The "tired" that you feel is a build up of CO2. The less oxygen there is to remove CO2 from your body, the faster you will become tired. The reason you don't feel tired while using a snorkel is you have a constant flow of oxygen. If you're just trying to burn calories, whether or not you're using a snorkel is irrelevant -- calorie burning is proportional to the distance swam. With that said, I'd suggest using a snorkel, as it's easier on your lungs and very efficient.

calories are burned as a result of work exerted over a period of time. Generally, burning calories causes a certain amount of exhaustion. For instance if you walk for one hour, you will feel somewhat tired, but if you run one hour you will feel more tired. That implies to me that you aren't working as hard with your snorkel.

This is one of the weirdest questions I have heard-no offence. But im not sure. Swimming an extra 30 lengths would make you burn more calories, if you kept the same pace. Snorkels only reduce the need for you to turn and breath, which doesnt have much effect on calorie burning. Going further with more effort are 2 of the key things related to calorie burning. So if you find it harder to swim with a snorkel, and can go much faster, then they will help you burn more calories!

While snorkeling you probably wouldnt notice doing any work... so i would say go snorkeling!! =)

No pain no gain.

why not do a bit of both i do :)

I know I feel like going to the pool to swim laps way more frequently with the swim snorkel than I ever did before I bought it, and yes, I also can swim longer distances too. Both contribute to calorie burning. So in short, yes, the snorkel is better. Sure, you're not going to race (conventionally) wearing a snorkel, but if your goals are just to be active and to burn calories, who cares what race regulations are or what the expectations/reactions of your swim team or the others at your local pool are?