i was vounteering with drops in the ocean for a few days, originally signed up just for night spotting shifts with possibility to help during the day too but when saw that daytime is either storage organisation (for very lovely people though) or teaching (two teachers per class) i prefered not to.  there were other incidents that put me off from further volunteering with them. as one of their full time volunteers said, she chose them because they had nice website, clear and with good pictures, please don't repeat this, do your research!