How many calories do you burn swimming aggressively for 2 hours?

Look at this website

I'm not entirely sure, I've been swimming for 10 years and swim 2 hours hard everyday, I remain a pretty constant weight, that could be because us swimmers have huge appetites;) and I just thought I'd point out the other answer, was copied from a question two years ago.

swimming for two hours its actual nothing, you can swim for 3 hours and you would use 600 calories, its a fact, i swim 10 Km a day which should take me 4-5 hours, of couse i dont swim 5 hours straight, but you surely get me, and 600 calories is ALOT, a normal person consumes around 3000 calories a day, this means your taking almost a quarter out of your daily calorie income, dont swim 2 hours straight one day, swim 45 minutes everyday, u'll get fit in the blink of an eye