Guam?

So this one is a longer story

For Father's day I asked my dad what he wanted me to draw him, so of course he said "Whatever you want!"
I know... Tons of help...
Anywho after a while I got "Ocean" out of him, but he still wouldn't choose a character, saying I could draw whoever, OC etc. Since my dad likes Yamada and the 7 Witches, I thought I would go with my OC Nagisa, since the water in Guam is pretty and in the manga they go there on a school trip.
I'd draw BC water but our fish are kinda ugly... We have pretty starfish though!

But yeah, sorry again the photo is terrible, I really need to get a scanner... 

Mediums - Watercolour, Gouache, Copics, Multiliner, er...