Yeah - it really is a good idea to charge the batteries before the dive! 
As for You'r shots, I think they are quite good for first try!
I would try to shoot more upward angle (specially shots 3 and 5 are not the best IMHO because of the "birdeye view")
Allso I would prefer a blue backround of the water column for negative space on shot 1 and maybe some amount for shot 4 as well. Allso the first shot does not seem to have any extra light from the flash - looks like it's all natural light there..?! Alltough it's a very nice portrate 
I like the second one, but I would do a little tighter crop on it or try to reshoot it closer.
Well done!!!
Just my 2 cents
Cheers
Karel