In fact one of the 2 seahorses I've ever found unaided was in the sand on the way out.
Nice! I remember Leanne finding a tiny pink frogfish near the exit at Tori's Reef once. It was only in about 6 to 8 feet of water but we never would have seen it if we'd been surface swimming.
Anita & I I found the little guy below in the shallows near the public exit at Bari. There were two other diver pairs on the surface and several snorkers in the area and all missed it because they weren't looking closely for anything interesting right there. The image is a screen capture from GoPro and the color is wrong because the water was to shallow for even my lightest filter. (I was too distracted by the unexpected discovery to remember to take it off before filming.)