Fluid

I dropped off the side of the dive boat the other day to play with these silver sides schooling around the jetty. This many fish schooling becomes like liquid silver flowing fluidly around obstacles and divers.

There's a reason for this of course - everything eats silversides and this is their best defence. Of course whilst everything else was trying to eat silversides, this chap was sneaking up with a view to eating everything else and in the process scaring the living daylights out of me when he appeared a foot away from my ear: