The adventure started the night before. I checked my alarm. I brushed my teeth. I checked my alarm again. I went to the bathroom. I checked my alarm a third time. I climbed into bed and lay down. Then I got up and checked my alarm.

"Don't oversleep!" I said again and again.

The alarm went off, and I was instantly wide awake. Today, it was my turn! I carefully made my bed and slipped down off the hanging bunk. I made my way to the hallway where I waited for Tom. We'd made a pact the night before to meet each other in the hallway. If either one of us didn't show up, we were to go find and wake the other up. Tom stumbled out of his room looking barely awake, but starting to get that look in his eyes. Today was our day to dive in Alvin!

I made my way to the computer lab to check my e-mail and then up to the galley to grab a light breakfast. Finally, I wandered out onto the fantail in plenty of time to see Alvin being brought out of the hangar and loaded with the weights that would take us to the bottom. After the thorough pre-dive check, our Pilot Pat Hickey entered the sub and then, after a few more minutes, it was Tom's and my turn.

I carefully climbed down the ladder and into the sub. I was assigned the port-side position and Tom the starboard. After several systems checks, we were picked up by the A-frame and lowered into the water.

Pat said, "Keep your eyes open. There was a big yellowfin tuna swimming right behind the boat before we got in." Sure enough, Tom and Pat both caught a glimpse of the magnificent fish. I wasn't as lucky.

The swimmers detached us and, after final surface checks, we began our descent. It takes about an hour and a half before you reach the floor, so Tom and I had a chance to familiarize ourselves with the controls of Alvin's video cameras, and we took some shots of the inside of Alvin using a digital camera. Tom and I also practiced using the Sipper, one of the important pieces of scientific equipment. As observers, we had to switch the cameras and take pages and pages of notes documenting when, where, and how things were done.

After a few hundred meters, we had pretty much lost all light, and the inside of the sphere became moist with condensation. It's a little strange to see so much moisture inside the submersible, but I had been told this was normal, and had to do with the temperature difference between the outside and the inside. I looked out my port and began to see bioluminescent fish.

"Tom, look out your port!" I exclaimed.

"Ah, that's nothing," said Pat. "Wait for the real light show."

As we descended, I discovered that he was right -- the bioluminescent show was more than I could have imagined. I couldn't see anything out my port except thousands of little lights. It was almost as though the fish were as curious about us as I was about them.

As we neared 2,400 meters below the surface, Pat flicked on the lights. The anticipation was too much, my face was pressed to the port. We were looking for the Large Volume Water Sampler (LVWS), which had been dropped the night before. As the floor came into view, I saw black rock that looked liked cool lava.

We found the LVWS right in front of us, a testament to how good the navigation system of Atlantis and Alvin can be. Once on the bottom, I was a little cold, but I took out my sweater and wool hat that had been so carefully loaded for me by the Alvin pilots.

We positioned the LVWS at a site called M vent and flicked on the pump. The LVWS began filling with diffuse flow water. Diffuse flow occurs in areas where the superheated water of the vent comes into contact with the very cold water of the deep ocean. We could tell that the water flow was diffuse because the water shimmered. After we set up the LVWS, we were off to accomplish other objectives.

First on our list was the Sipper work. We took 11 samples from Alvinella tubes -- each sample required that Tom and I operate devices inside the sub, take careful notes, and switch cameras multiple times. There was a lot to think about!

After the Sipper work, we went back over to the LVWS and released it. Pulling a pin activated the floats, and the LVWS floated to the surface. We, however, went back to collect worms.

At M vent, we saw the incredible structure that the Pompeii worms had built. There was so much life. The worms were very active, reaching out of their tubes and exploring the water, their bright red gills moving back and forth. The pictures captured by the cameras paled in comparison to what I could see out my own port.

Pat is incredibly skilled with the manipulators. He expertly grabbed clumps of Alvinella worm tubes and shook them out onto the top of the bioboxes. Then he used something called a slurp gun to capture the worms before putting them into the Artie. It was an awesome sight to see, and, before we knew it, we were done.

After M vent, we proceeded to Q vent, where Pat used the manipulators to create a space for one of the frying pans. By knocking down an existing chimney and placing the frying pan on top, scientists can collect parts of the vent as it begins to regrow.

While we were working on the chimney and frying pan, we had the opportunity to talk on the phone from Alvin to some school groups. It was amazing to talk to students at my old elementary school from 2,500 meters below the surface of the ocean. That was great!

But as soon as we were done, it was off to a site called Tica. At Tica, we collected vent crabs, and then it was time to move onto the Bio9 vent. At Bio9, we collected a device called the mosquito, which collects thousands of data points. After that we dropped our weights and headed to the surface.

All in all, it was an amazing experience. I could try and describe for you everything we saw -- from the amazing black smokers to the strange sea cucumbers, from the deep-sea fish to the bright tubeworms, from the charismatic vent crabs to the mussels and clams -- but the beauty I saw at the bottom of the ocean is impossible to fully describe in words.

Upon our return to the surface, the Alvin and Atlantis crew brought us back on deck. I was amazed at how smooth the retrieval process felt from inside Alvin. As I departed Alvin, I was handed back my sneakers, which were very wet. As it turns out, my sneakers had been attached to Alvin before we dove by Bruce Strickrott, one of the Alvin pilots, and so my shoes actually traveled to the bottom of the deep ocean. That was a very funny prank, Bruce! Once we were back on deck, the scientists had a welcome-back celebration (which you can read about in Karen's journal) for Tom and me.

I'll leave you today with the words of William Beebe, the first scientist to descend the ocean depths.

"If one dives and returns to the surface inarticulate with amazement and with a deep realization of the marvel of what he has seen and where he has been, then he deserves to go again and again. If he is unmoved or disappointed, then there remains for him on earth only a longer or shorter period of waiting for death." -- William Beebe, Half Mile Down

"Inarticulate with amazement" ... Yeah, that sounds just about how I feel right now.

A small electronic zipper message board hangs on the starboard wall of the Main Lab and provides up-to-the-minute news from Alvin while it's diving. Toplab gets word from the sub and passes it along to the zipper. This morning, the humorist posting the news writes, in red dotted letters that pass slowly before our eyes:

SLOWLY ZEE SMALL SUBMARINE DEZENDS INTO THE INKY BLACKNESS ...

Within the hour, the message changes: ON BOTTOM.

I woke this morning with a special excitement because today Mike League was going into the sub along with Tom Niederberger -- both of them are newbies -- and Expedition Leader and Pilot Pat Hickey. Mike's going to be in the sub for the last Phone Call to the Deep. The call goes beautifully, with questions answered by Chief Engineer Jeff Little about how Atlantis stays in one place without an anchor, Dr. Horst Felbeck about the life cycle of Riftia pachyptila (the giant tubeworm), Pilot-in-Training and Alvin Technician Anthony Berry answering a question about Alvin safety, and Ordinary Seaman Kevin Threadgold weighing in on how to keep in shape aboard Atlantis.

Since I'm in Toplab, I poke my head into the bridge to say hello to Second Mate Craig Dickson. He knows I'm working on a book about navigation and has offered to show me a few things. We start in the chart room behind the bridge, where he shows me the charts for the areas that Atlantis will pass through this week as we 'transit' from 13º north to San Diego. We'll be steaming north close to the coast of Baja California and various coastal islands. I ask if we might see migrating gray whales.

"Maybe," says Craig, looking as if he hopes to see whales too.

It turns out this is my day to learn to use the sextant, too. My earlier experience with sextants was at the exhibit for the Shackleton Expedition to Antarctica at the Museum of Natural History in New York. The exhibit demonstrated how difficult it was to use this instrument to find your position by screening a video of a surging sea behind the sextant that you were looking through. Using Craig's sextant was easier because Atlantis was stable, in quiet seas, but it was still pretty difficult to get the sun to sit precisely on the horizon to get an accurate "fix" and find your position. Eventually, I managed and followed Craig as he made the calculations that confirmed we were indeed at 104º20' west. I head back in time to see Alvin recovered from the ocean.

As we prepare for Mike and Tom's return from their first Alvin dive, we encounter a small obstacle. The ice machine isn't working, so some brainstorming happens among the scientists. The problem is solved with latex examination gloves filled with Kool-Aid. Barbara Campbell adds a creative touch: fruit for the guys to hold in their mouths while being doused with Kool-Aid glove balloons. Each has a fruit symbolic of their country: an apple for American Mike and a kiwi for Tom, who's from New Zealand. They do their duty as newbies and then, dripping with pink Kool-Aid, bite into the fruit as they stand around chatting, eyes glowing, about their experiences at the hydrothermal vents.

In the computer lab, I've left presents on Mike's desk -- a little remote-control sub and a sign with the name of his dive -- #4070. Every morning before Alvin launches, a technician holds up the sign in front of each camera to prove that it's working for the pilot. I snagged the sign out of the top of the deck garbage can as a souvenir for Mike.

Mike is pretty tired after his dive, but we have to stay up late to complete the Web materials for the day. We're busy here, loading photographs and video from the ship's Web site (which includes Alvin stills and video for each dive), coordinating pictures sent to us by other people on the ship with cameras (including Noel Masias and Craig Cary), and gathering and sorting shots from our own cameras. We've got journals to put the finishing touches on, the dive log to edit, and extreme experiments to consider and figure out.

We've been getting some nice messages from "the beach," as Craig Cary calls the land, and that keeps us jolly. So do Dave Simms and Kazumi Baba, our shipboard science support group technicians. Kazumi can fix all kinds of computer problems and answers so many questions, and Dave stays up late every night to send out our package at 11:30 p.m. Sometimes while we're all working, the CTD is coming up, so we take a break to run outside in steel-toed shoes, hard hat, and PFD to help with the hooking poles that keep it steady as it is raised onto the deck. Dave is in charge, usually wearing his hard hat, which is pretty funny since it's in the shape of a white cowboy hat. Dave's from Texas so, of course, he has to have a cowboy hard hat!

I take the long way to bed. Instead of climbing three staircases to my cabin, I walk through the Main Lab and out onto the aft deck, which is strung with Christmas lights. Using their light, I climb one set of stairs to the first deck. (Gavin Eppard says there are nautical terms for these decks, but they don't really use them. Instead there's the main deck, 01 (they say 'oh-one'), 02 ('oh-two'), and the bridge.

It is absolutely pitch black, the darkest place I've ever been. But I know there's another set of stairs right ahead of me, so I pad along carefully until I find them. Now I have to stand still for a few minutes, waiting for my eyes to get used to the dark, and praying that nobody comes along and scares me to death. (That happened to Craig Cary the other night. He was on deck waiting for his eyes to adjust when Craig Dickson, who had been out for a while and could see, came along and stood right next to him. I would have liked to have been there, but it's fun to imagine!)

The creepy darkness is worth going through to get to the 02 deck, which is faintly lit by the green light from Atlantis's starboard beacon and the red light from the one on the port side. I untie the plastic lawn chair that's sitting there (it has to be tied to the rail to keep it from blowing off the deck and into the ocean) and lean back until I can see the sky.

It is absolutely stunning. Last night, there were big black clouds hiding many areas of the sky but tonight it's clear -- right down to the horizon. Imagine that a hose ran up the underside of the earth and stopped just below the horizon, and that the hose was spraying stars across the sky. That's what the Milky Way looks like, crossing above my head in a ribbon of misty white.

Out here, the stars bounce back and forth. No they don't; the boat does. But it looks like the stars do, in the same way that when a train leaves the station you can't tell for a second whether it's your train or the one beside it that's moving. The stars are many and large and small and tiny and in mists I'd never notice at all, at home. There are different colors, too. There are shades of white and yellow, blue and peach. What would happen if I just fell asleep here ... ?

I don't. I make my way around the corner to the 400-pound door to the hall where my berth is. That's one of the great things about Atlantis: no matter what incredible place you've just been, whether it's the bottom of the sea or another arm of the galaxy, bed is always very close at hand.