Lanai Lookout, O'ahu Hawaii
Color Key: Sea sick green = tunnel/cave. Light blue = shallow (< 10 foot deep) water. Dark blue = deep dive-able water. Yellow = high dry land. Orange/Red = low dry land or dry crevasse. Gray = paved road. Dark green = bushes.
Location: Midway between Hanauma Bay and Sandy Beach / Blowhole, on the southeast side of O'ahu Island, Hawaii, USA.
Special warnings: This is a tough dive, not the least because if you enter on the east end, you have no way of immediately exiting. You MUST exit on the west end, at the tip of the J-shaped cove. Please also be aware that the orange portions of the map above are sharply sloped rock. If you have weak legs, bad knees or slippery shoes, maybe this isn't the dive for you. There's no phonebooth, no lifeguard, and no bathroom. The nearest place with all these is Hanauma Bay to the west and Sandy Beach to the east. There's no shade, and the sun's strong here, so bring sunblock.
Special attractions: Adrenalin ride. Frequent lobsters, fist-sized humpback cowries, spotted eagle rays, and turtles. Occasional views of offshore humpback whales, in season (Oct. ~ May). Rarely, you may hear pips and squeaks of far-off spinner dolphins or groans of far off whales singing.
This dive begins in the parking lot. Please take precautions against car break-ins. Ideally, leave one person in the car (not merely nearby). Break-ins are very very common here.
Next, quiz divers exiting the water. Ask about visibility, current, and wildlife.
Personally inspect the exit point (the jacuzzi-like spot in the J-shaped channel at right). Expect strong surge in this channel. Leave at least 200 psi / 20 atm in your tank so when you're in this channel, you can use the rocky bottom like a ladder, leapfrogging when the surge pulls you forward and hanging on while the surge pulls you back. If this is your first dive at Lanai Lookout, strongly consider using this point as both entry and exit point, to gain familiarity with the exit.
Assuming you have some experience at this site, or are going with a guide who knows the site well, this is how it's typically done:
1) Gear up at the parking lot
. Leave your
wetsuit open and
loose (to prevent heat exhaustion) and let your fins hang from your
BCD's chest strap (to leave your hands free). Walk east along the
road. Enter the first valley on the side of the road AWAY from
the ocean. In the valley you'll find a door-shaped tunnel 
that goes under the road & out to sea. Walk through.
Use a small divelight if you have one.2) On the far side of the tunnel, go west and look for hand- & foot-holds
to lower yourself to the sea-level
shelf. Be
cautious when yuo get down to sea level-- the rock here is slippery,
and occasionally waves come over the rocks.2) Walk east and look for a shallow tidal pool near the base of the cliff
. It often has a few small reef fish
in it. Use
this shady spot to catch your breath and assess your courage &
desire to continue. From the tidal pool walk south onto the
slippery, jagged, rocky point of land. Keep the
mickeymouseglove-shaped cove 
on your left. Don't consider
entering that whitewater mickeymouseglove cove under any circumstances,
even on the calmest
days. Go about 2/3 of the way out onto the broad triangular
point, to 
. This is your entry point.
It's not clearly
marked, so find a diver with experience here, to show you the right
entry
spot. Preferably a diver with no evidence of scars or head
injuries. A mistake here could ruin your whole day. ;^D3) Use a buddy's shoulder for balance, and put on your fins a few feet inland from the entry point. Take turns going out to the entry point, and use the giant stride entry to go in. Time your entry so you enter when the wave is high. Strongly consider havign all your team members enter with BCDs DEFLATED, so they can assemble underwater. The water at the surface here is whitewater with 0 visibility and a frequent strong surface current, but at the bottom 30 feet down, visibility is typically 35 to 40 feet, with no discernible current. Carefully balance air consumption and experience, when deciding who will enter the water first here. A large team may require several long minutes to enter, and yet one wouldn't want to pressure inexperienced divers to enter if they're intimidated. Make no mistake... this entry is an adrenalin junky's ride. Even hardy divers will find their pupils contract & become pencil-sharpener pinpoints. Be VERY aware that anyone entering here is in for a minimum 40 minute / 40 foot dive to reach the exit.
4) Once your team is assembled underwater, take stock of your surroundings. You'll notice 3 tunnel entrances in front of you: North, North-West, and West. The shallow one to the north leads to the mickeymouse-glove cove. Don't go there under any circumstances. It's dangerous, surge-driven whitewater and sharp rocks. The deep, small entrance at the north-west is a silty small cave
. Occasionally
small-claw lobster live there, but
be aware that the bottom inside is easily stirred up & can leave
you in 0 visibility conditions just a yard from the cave
entrance. The huge tunnel to the west should take your full
attention.5) If your team knows this site well, and you are all low-air-consuption divers, consider visiting the fishtrap
.
This is a fish-census trap operated by the University of Hawaii, so
please don't release the fish. They will be released unharmed
within days, after being counted by University marine biology
students. Occasionally, wisecrackers have left inflatable party
dolls and inflatable party sheep in the trap. If you find one of
these, please contact the University. ...And send me a
photo. From the fishtrap, you can swim due west and go around Shotgun Point
. Shotgun point is named after the
murder weapon found there
by divers in the mid-1990s. Whether you go around Shotgun Point
(unusual) or like most divers head through the large West Tunnel
mentioned above, you will head due west through a field of boulders
until you reach the deep, massive wall of Lanai Lookout's large central
point. The top of this wall is a shelf only 5 to 10 feet
deep. Along the edges of this shallow shelf you can always see
black, shiny, fist-size humpback cowries. On extremely calm
days-- perhaps one day every year-- you can get up onto this shelf and
almost reach dry land without being battered and cheese-grated by surge
and surf. You won't be that lucky.Instead, whether swimming along the edge of this shelf, or simply moving along the bottom edge of this deep underwater wall, move to the left (south) following the wall. You'll see "pebble-in-a-puka"
, a car-size boulder in a bowl-shaped
depression, at the top of the
wall as you reach 50 feet from the southernmost point of the
wall. At this point, you should have a minimum of 2000 psi / 175
atm in your tank.6) As you round the southernmost tip of Lanai Lookout, keep an eye on the deeper water. You'll see a turtle or spotted eagle ray on about 1/3 of your dives here. Also look carefully in long vertical notches in the wall
, where lobsters and
"7-11 crabs"
often hang out. A 7-11 crab
is a soupbowl-sized light green crab with large rust-colored
spots. Like a living bowling ball that's been smooshed and
spraypainted green and... OK, so it doesn't look anything like a
bowling ball or a soupbowl. But if you look at it from the front,
it's got 7 spots. Viewed from the back, you see 4 more, making 11
total. 7...11. Get it ? Good. :^D This will be
the deepest part of your dive, with
a maximum depth of about 70 feet unless you're tempted to swim away
from the wall into slightly deeper water.7) After rounding the tip and passing Lobster Notch , you'll find that the bottom becomes less rocky and more like deeply wavy salt-and-pepper-color sand
. At this point,
you should have
at least 1200 psi / 150 atm. On extremely calm days, you may want
to venture up onto the shelf here, to visit "popcorn alley" 
and
"popcorn glove" 
. These shallow
valleys in the shelf are
named after the way that fist-sized rocks are tossed about in these
depressions like exploding popcorn, even on the calmest days. On
second thought, don't go there. Bad idea.8) Keep your eyes open for a van-sized cave
with a huge hole in its ceiling.
Counting the hole in the ceiling, it has 4 entrances, so it's often
called the 4-mouthed cave. This is
your signal that you're near the exit. If you're anxious about
finding the exit cove, this is an excellent place to surface briefly
("prairie dogging") to look at the surroundings. Any closer to
shore, and you're dangerously shallow & surrounded by powerful
surge & waves that may dash you onto the rocks. 9) If you have oodles of air left & would enjoy an additional adrenalin-rush, consider visiting Windchime Alley
. For most
divers, though, Windchime Alley is a bit too challenging & comes at
a time when the diver is most likely low on air.This rather deep (20 foot) hallway-shaped valley in an otherwise shallow shelf is named after the pleasant tinkling bell sound caused by wave surge jumbling rocks, broken shells, and bits of antler coral in the bottom of this trench. Enter at the south end of the valley. Use gloved hands to hold onto the top lip of the valley here. Wait until the surge pushes you in the right direction and then swoop down into the valley like Superman (tm). DO NOT try to go too far north in this valley, because it gets very shallow and sharp at the north end.
10) Note that the map shows a "false exit channel"
. On a day
with poor visibility, even cautious experienced divers can mistake this
false exit channel for the real thing, and find themselves trying to
exit the water in a truly nasty spot. To make this exit both
safer and more exciting, strongly consider swimming past the exit
channel and the window-sized peep-through tunnel 
. Instead of
a direct assault on the exit channel, enter the true exit channel via
the broad tunnel marked 
on the map. This
tunnel is excitingly dark and
twists up, down and up again. On the other hand it's always 2 divers
wide and leads
infallibly into the exit channel avoiding any chance of going in the
false exit. Bring a dive light if you can,
because this dark tunnel is creepy and frequently home to
large football-size pufferfish that can scare you in the dark.
Bring a light, or risk adding organic
earth-tone liquids and solids into your otherwise clean shorts. At all costs, avoid the shallow, surge-driven "cheesegrate"
. This is not a place to hang
out. By way of illustration, consider that one of only two times
I've ever seen my old instructor look frightened was the time he went
up onto the "cheesegrate" to rescue some stranger who was caught in the
shallow, sharp, surge-ridden rocky shelf there. The lesson I took
away with me that day was, "Sometimes you can't help without becoming a
victim yourself."11) Once you're in the true exit channel, shaped like a "J", stay on the bottom. (The surface has a rough current.) Hang onto the rocks with gloved hands while the surge drives you out to sea, and let the surge carry you forward when it's moving in toward land. Work your way to the end of the "J", where you'll find a 2 foot deep Jacuzzi-like exit pool
. You can sit
along the perimeter here and
relax while taking off your fins, waiting for your teammates, and
gathering energy for the long climb 
back to your car . Remember to clip your fins onto
the chestclip of your BCD, to leave your hands free for the climb12) Beginner divers may prefer to enter and exit at the exit point
. 13) Extremely advanced divers with excellent air consumption may think about entering at the J-shaped exit cove
, then making an extremely long shallow
wall dive
westward finishing up in "Toilet Bowl" or on the main beach of Hanauma
Bay. Consider, however, that this extreme drift dive is a minimum
1hr. 25min. dive with no exit points en route and no way for people
onshore to watch your progress. There are also
frequent strong currents at the mouth of Hanauma Bay that can make the
dive difficult. This course should only be considered by divers
with tons of experience at Lanai Lookout, Toilet Bowl,
and Hanauma Bay. You'll also need a support driver to pick you up
at Hanauma Bay, or you're facing a staggering 30 minute hot wet walk
back to Lanai Lookout.