The first episode of H2O is Metamorphosis, where the girls (Cleo, Emma and Rikki) visit the mysterious Mako Island and turn into mermaids when they enter the moon lake during a full moon.
Metamorphis
Season 2, episode 2: "Control"
The awakening
It's explode 1
H2o is on tv episode 1 and 2 episode 3 should come soon but episode 4 is if number 3 is succsesful
It's episode 78, "Graduation."
They just came out with new episodes of h2o I think a season 4!!
the finale
http://vids.tv/H2O-Just-Add-Water/tv/season-2/episode-12-Monster
I know they kiss in espisode 23
The last episode of H2O:Just add water is season 3 episode 26 and it is called graduation.
through links on http://www.yidio.com/show/h2o-just-add-water