Greetings to everyone again! Last week’s adventure (Diving with “friends”) is not part of the norm down here. We like to keep things very simple when we can, and diving is no different. You have read in Chuck’s and Maggie’s journal entries about getting ready and getting out to the dive sites. Now, I will let you in on the diving experience! I will talk you through a normal dive down to 130 feet…then I will tell you about a slightly unusual after dive trip.
After my buddy (Maggie on this dive) and I are fully suited up, we enter the water. I do a back roll off the side of the zodiac. That means I check for ice behind me, and then just lean back and pull my feet up. I enter the water on my back and right myself once I am in the water in order to get heads up. The initial sensation of the icy water hitting my face is quite a shock. I signal to the boat that I am okay and look for my buddy. The zodiac has now backed out of the area and Maggie and I are bobbing in the water.
We signal we are ready to go down and I open my “dump valve” located on the shoulder of the dry suit. When the valve is closed, no air gets out of it and I am relatively airtight inside my suit. Once I open the valve, the air comes rushing out and I become less buoyant. I also dump all the air out of my buoyancy compensator (BC). Even with 140+ pounds of gear and weight on, I need to get rid of almost all the air I possibly can just to get under the surface.
Once I am under the surface, I make sure that I keep an eye on Maggie. The shallow water is very murky due to phytoplankton and glacial flour (sediment deposited in the water column from glacial ice when it melts). The water moves up under my hood and now my head is completely wet as well. It does not ever seem that cold to me due to the hoods that I have on and the ability of my “hot head” to heat the water around it sufficiently.
While I am descending, I begin to notice that my suit is trying to squeeze me. While in the boat on the surface, I was experiencing 1 atmosphere (atm) air pressure (14.7 lb/in2). Now, for every 33 feet I descend, I add another atm. This means that at 130 feet, I am experiencing approximately 4 times the air pressure on the surface. This means that the air in my lungs is compressed 4 times more than at the surface and this also means that I go through my air 4 times faster than I would at the surface. In order to make diving comfortable, I must put air into my suit. As I descend, I press my inflator valve and air runs through a hose from my SCUBA tank to my dry suit.
This counteracts the squeezing and makes me a little less negatively buoyant. If I did not add air, not only would the suit squeeze up around me and be very uncomfortable (actually painful), but also I would soon by about as buoyant as a rock! I like to make my descents in as controlled of manner as possible, so air is a very good thing to add to my suit.
Once Maggie and I get about 20 feet down, the water starts to clear up. We want to get down to 130 feet as soon as safely possible in order to maximize our dive. We don’t collect anything on the way down; we simply descend. Usually is takes about 3-4 minutes in order to get to our maximum depth. We level off at about 125 feet so that we don’t go any deeper than 130 feet (our maximum allowable depth).
This dive was made for the main purpose of targeting some of the deep-water sponges we needed. This particular dive site has an underwater wall down much deeper than we can go. We collect here because there are so many sponges and other invertebrates in such a small area. For several of the sponges we are targeting, we have never seen them above 125 feet, so we need to look in the deep range. The first thing that I do is get out my dive light. While the water is pretty clear, it is still quite dark down at this depth. I start to swim along the wall and find the first sponge we need right away. Maggie comes over and we collect it (usually only one person is needed to collect a sponge, but we have certain species that we do experiments on and they need to be collected differently). I then continue along the wall and find another sponge needed. We collect it and I look at my computer.
I have now been underwater for about 11 minutes and I am only allowed to stay at this depth for another 3 minutes before I would have to make a required decompression stop on the ascent. Knowing how long it has taken to collect these first two sponges, I do not want to spend more time down here. I instead decide to move higher up the wall and see if there are other sponges and invertebrates that I need along this area.
As I make my ascent, the air in my suit starts to expand. Luckily, my dump valve is automatic and it releases the air as needed on my way up. If I had closed this valve and then started up, I would be similar to a balloon and shoot upwards as my gloves would probably pop off (making my hands VERY cold) and my neck seal would either rupture or fail (either way sending bubbles by my face effectively eliminating my vision). The air in my lungs would also expand and possibly damage my lungs. All of these factors are just a few of the reasons that we make slow ascents.
On my ascent, I collect some other sponges that I know I need for feeding assays with the sea stars and I keep an eye out for anything interesting. During this time, I notice that my fingers are starting to get chilled, but my body is remaining nice and toasty! Maggie is right next to me doing her own collecting for the majority of this time.
When we get to 60 feet or so, the animal life has essentially been overtaken by the macroalgae. I put my knife and light away and signal to Maggie that we should go up to 25 feet. We do this and it is relatively calm, so I signal that we should go up to 20 feet. By now, my hands are quite cold.
Of course, as soon as I signal that we should go to 20 feet, I see a shallow sponge that I need and have to stay at 25 feet for a few more minutes collecting it. When I get up to 20 feet, the water is a little more energetic that I had thought it would be…and my hands are STILL cold.
We are moving back and forth hanging onto big plants trying to remain as stationary as possible, or at least at one depth. I then notice some more of the shallow sponge I want. I get my knife out and move toward it…and the surge moves me past it. I then let the surge push me the other way, and I use my knife to try and grasp the rock as I pass by. I am able to make one swipe at the sponge, but not enough to get it. The surge then brings me back by and I collect a small portion of the sponge. I do this for about 8 minutes getting tossed back and forth until I have bits of about 3 different organisms.
Maggie and I then spend a few more minutes just hanging out continuing our safety stop until I think we are ready to head up. I ask her if she is okay and she signals “yes.”
I then start to swim away from the island. We try to swim for about a minute out away from the island in order to give the boat plenty of room to pick us up.
Once at the surface, we signal we are okay to the tenders in the boat and wait for it to come and pick us up. We get all our gear off in the water and help the tenders get it into the boat, and then we proceed to get in the boat.
Once in the zodiac, we hear that there have been some whale sightings near where we are. The tenders ask Maggie and me if we want to go and see the whales or just head home. We both say that we should go to the whales.
We pull around Stepping Stones (one of the islands) and see another zodiac. It has been sitting in this one spot for about an hour with several humpback whales surfacing near them. They say that the whales moved away when we came near (the zodiac engines are pretty loud underwater), so they decide to head home.
We sit around for a few more minutes and then one of the whales comes up for air a couple hundred yards away. Then, another surfaces a little closer. Hla, who had been tending, takes pictures. We decide to head back to station because it is getting a little chilly for Maggie and me.
As we start moving, one of the whales is now in front of us and it might be 75 feet away. We stop the boat and they come up for air a few more times before we decide to head home. I have included some of the pictures that Hla took so that you can see what we see when the humpback whales come up for air.
So, that is what I would consider a very regular dive down here. The after dive whale sightings are very rare, but definitely appreciated when they do occur.
Thanks for following our “adventures” down here and I hope all is well on the home fronts…wherever they might be!