Scuba vs Freedive breathing patterns. can i do both?

[TNdiver]

I just got back from a trip to Maui and did both, for the first time really. I had done a little bit of free immersion in a lake here, but thats about it. The couple trips i did on scuba made me ALOT!! more comfortable in the water especially at depth. I didnt have any trouble after the scuba dives with trying to breath underwater, but as someone mentioned earlier, i always take my snorkle out right before i go under. In regard to air consumption i had an interesting experience. I was out with a small group (our motel had free pool lessons and did an ocean dive for around 85 bucks) , and on my second dive there were some younger guys with us (around 12 or13 i think) They ended up running almost out of air, and had to swim back to shore on the surface. At the end of the dive, after swimming back in using air right till the beach, i still had around 1200lbs left. We started with 3000. I dont know if freediving played a roll in that or not, but I personally think it probably did.