MilitantMedic:
...didn't get the chance to do a wet recce on that side while we were there... Our tour was confined mostly to the leeward side (facing Oahu) but from the top of the "head" it was easy to see the cliffs on the windward side and the blue color next to the island was just as dark and deep as far offshore; about the same look at a few spots on the Big Island's South Point. I'd say that it was an easy 60-80ft just off the cliffs and going way deep within, oh, 100ft offshore. It was a washing machine with a good backwash from the cliffs; comparable to Haunama Bay's Witch's Brew on a bad day. The seas at the time were running maybe 4ft. The leeward side was fairly calm with rolling swells and a noticable current running down from Kaneohe.
The island is surprisingly big; almost round. The high points are all on the Oahu-side. The center is a large bowl and mostly tinder-dry grass. We walked exclusively on the rocky areas, up to the summit and along the sea-level shelf which extends all along the Oahu-side. There were just too many ground nests to walk anywhere else. And of course, most of us got a bullseyed with a bird souvenir. Man, the opihi were huge; easily 2in.+ across.
I did get to do some snorkeling at the landing beach to out maybe 100yds. (Washed off the souvenirs, too.) (The sign warning against landing is surprisingly big; it doesn't look that way from Makapuu tho'.) The water was crystal. Large rocks with mostly encrusting-type lobe coral; some hard califlower corals; no finger corals where I was. Four turtles. Don't recall there being a whole lot of fish. On the paddle back to the Makai Range pier, the bottom was easy to see; depths had to be 30-40ft.
We didn't do the nearby flat Bird Island. But a friend who used to lifeguard at Makapuu used to swim out there for some spearfishing (yep, he swam all the way out, around, and back; a stone waterman).
