First dive at Darwin's Arch, Galapagos...
dropped to the rocks at 85' hoping to see hammerheads. After positioning ourselves to be inconspicuous (except for the bubbles)...we could see shadows at the very limit of visibility. The HHs were a little skittish at first and stayed out in the blue, but slowly over 10 or 15 minutes, they started to come in closer and cruise about.
One, then two, then five, then twenty, then forty hammerheads...they were thick in places. One stopped at a cleaning station near us and was just vibrating while it hovered in place as the cleaners were darting into its mouth and gills.
While enjoying the shark parade, it suddenly got dark. Assuming a cloud was passing in front of the sun, I casually glanced up to see the bottom-side view of a 40+-foot whale shark. Several pilot fish almost as large as me covered its tail, the immense size of this fish was hard to comprehend for a few seconds. My brain tried to process it as another hammerhead at first...uh, no.
As the whale shark glided motionless in the deep, everyone was high-fiving and acting giddy...on the way back to the boat, we were passed by a group of 20 eagle rays. Absolutely sensory overload...