Divers throughout most of the world rely on the buddy system. Unless you are connected to the surface with both air hose and communications gear, there is always at least one diver with you. And even with surface-supplied diving, a "stand-by" diver is always suited up and ready to go help you at a moment's notice.

We adhere to the buddy system at all times, usually diving in pairs but occasionally in threesomes. Threesomes are usually only a wise idea when the visibility is good, but we've been very lucky with that here.

Last week Bill and I headed to a beautiful underwater wall on Cormorant Island. Cormorant is the most distant island from Palmer that is still in normal small boat operating range.

It is named for the Blue Eyed Shags that nest on the island's steep above-water cliffs, but there is also a modest-sized penguin rookery on the island.

During our last expedition here we made one dive on the Cormorant Island wall and collected several species we found no where else or only in small amounts elsewhere. So, we were anxious to get back.

It was an absolutely beautiful, sunny day as we motored out in our dive zodiac. Jim and Maggie were our tenders. We found the wall with no trouble, just off a large rock that towers up from the ocean just off the southeast corner of the island. Our hand held GPS (Global Positioning System) device confirmed the spot but we knew it just from the above water topography.

We drifted a bit offshore as Maggie and Jim helped us into our dive gear and then we motored back over to the edge of the rock to drop into the water. Bill and I then dropped down under the surface and rapidly made our way to our agreed on initial depth of 125 feet. We passed over many of the things we planned to collect on the way down but intended to get them on the way back up.

The way we plan all our deeper dives is to drop immediately to the greatest depth planned. When the depth is as great as we were going (our deepest allowable depth is 130 feet) we only have a couple minutes to collect before we have to make our way to shallower water. If we dally on the way down, our dive computers might not even allow that within the strict safety limits programmed into them.

When I got to 123 feet I found myself in a field of one of the macroalgal species that we are placing special emphasis on this year. It is one that we usually only find in small to moderate quantities, but it was covering the wall there. I looked up to check on Bill. He was right above me and doing fine, so I started collecting the macroalgae as quickly as I could. I knew that in a couple minutes I'd have to be on my way back up.

I looked up again after a few moments and saw that Bill was still six feet or so above me. I was surprised that he hadn't come all the way down, but he was getting out his knife so I assumed that he'd found one of the sponges we were looking for. We usually use our knives to cut the bases of the sponges from the rocks to collect them. Mindful of the brevity of our stay, I turned my attention back to stuffing macroalgae into my collecting bag.

A few moments later, Bill appeared beside me and gave me a hand signal. It turns out that we weren't a twosome buddy team after all. Two person, yes. Twosome, no. Little did I know that right after I'd first checked on Bill a third "diver" had appeared with us. Unfortunately, it was a most unwelcome one, a seven- or eight-foot leopard seal and it had been arching back and forth off the wall behind me the whole time we'd been at depth.

Bill had been getting his knife out but not to collect sponges but rather to bang on his tank to get my attention. When the seal moved away a bit, Bill came down and gave me the leopard seal sighted signal. Beautiful collecting spot or not, it was time to get back to the surface.

Leopard seals have never attacked a diver underwater. But they do eat seals that are bigger than divers and have been known to attack zodiacs — even tied up at the dock — so standard operating procedure is to get out whenever one is sighted. Particularly when the one you see is only a few feet away!

Bill and I hugged closely to the "bottom" as we made our way up. That was easy to do since the bottom was a vertical to nearly vertical rock wall.

The seal stayed with us the whole way up until we got to a depth of 20 feet, arching back and forth in semicircles around us from the wall on one side to the other.

At 20 feet we paused for a safety stop and it went up to the surface after about two minutes.

Thinking that we had a chance to get out, we slowly headed back up. Although safety stops are a good idea, they are not required by the dive tables and can be skipped in an emergency. The leopard seal's passes were getting closer and closer. When I'd first seen it at depth, it was coming within six to eight feet of us. By the time we'd gotten to 20 feet it was more like three or four. With the seal making these increasingly bold maneuvers, it seemed like an "emergency" to Bill and me so with a glance and nod to each other we headed on up.

Apparently the seal had other ideas. Normally we try to make safety stops at both 20 and 10 feet. The seal had only gone up for a quick breath and it came right back down to us when we were at 10 feet. So, a 10-foot safety stop it would be!

But the leopard seal kept getting closer and closer. I am sure that once when Bill's back was turned it was only a foot or so from his tank. Neither of us ever felt like the seal was at all threatening. Clearly, it was just being curious about these strange red and black covered creatures who where constantly blowing bubbles. However, a thought did cross my mind that it might get curious about what we tasted like.

After we'd been at 10 feet for four minutes, Bill and I looked at each other again. We both had lots of air left after our abbreviated dive and could have stayed at 10 feet for at least another half hour and probably a lot longer than that. But the seal kept getting closer and we both sensed that there was no reason to stay any longer. Our dive computers were telling us that we were well in the safe zone for surfacing (we always are, but we were particularly so after the "safety" stops and our short dive). So we looked at each other and headed the last 10 feet up the wall to the shore.

When we broke the water we gave Maggie and Jim the emergency signal — simply waiving your hand and arm side to side; if everything is OK you put your hand on your head. Standard leopard seal sighted protocol is to get out of the water onto the shore if you can. Fortunately, we found ourselves on a small flat rocky ledge right at the shoreline. We crawled up onto that as Jim and Maggie drove the zodiac towards us. They had recognized what was going on immediately and headed right up to us on the rock. There is only one reason why divers here, who are wearing restrictive dry suits and something like 80 pounds of bulky gear, crawl up onto shoreline rocks. Total time from entering the water to surfacing beside the rock ledge was 14 minutes. The first two were sans the third "buddy."

Jim ran the zodiac up onto a rock at the edge of the ledge beside Bill. We were all working as quickly as we could but methodically and without undo haste. Bill handed his collecting bag in to Maggie, and then I passed mine to Bill to hand in. Because of the positions of the boat and us on the ledge, with some help from Maggie, Bill was able to stand right up and roll over the side of the boat without even taking his fins off. It is the first time I've ever seen a fully suited diver get into a zodiac (almost) by himself. Maggie tells me that he landed with his tank momentarily right in a plastic bucket we always bring along to keep collected organisms in on the way back. Two points for the slam dunk! While that was going on I got out of my fins so that the one big step I had to make to get over to the boat would be easier. Maggie helped me in and the adventure was over.

As I said, the seal never seemed threatening. Our response in getting out of the water was one of measured caution, not a reaction to any overt or perceived threat. Just the smart thing to do when a leopard seal decides to be your dive buddy. But, I sure wish I could have collected some more of those macroalgae before the seal showed up!