Surface Supply
The last bit of my training that is required before we can collect the marine worms necessary for Dr. Marsh and the team's experiments is that I have to learn a different way to dive. So far, we have been doing SCUBA dives, which involve breathing off of regulators from air tanks. For a few of our dive sites, we need to be completely sealed from the water and so we will use a system called surface supply diving.
Major difference
The biggest difference between SCUBA and surface supply is your air source and what you wear on your head. With SCUBA, you wear a mask and hoods, but the water can touch around your lips. With surface supply, you wear a diving helmet connected to an air hose. The air is passed through the hose from the surface; hence, surface supply diving.
Here's diver Steve Rupp on SCUBA. Look at his face.
Here's diver Steve Rupp on surface supply. See the difference?
What's it like?
Underwater, surface supply is actually pretty cool. Since your entire head is encased in the helmet and surrounded by air, you feel warmer. Also, since there is a tube to pass the air down to you, there is also the opportunity to pass a communication wire to the diver. That's right, people on the surface can actually talk to the diver below. (I find this really helpful during my surface supply dives.)
Here you can see the surface supply hose and the box, which regulates the air and provides the communication.
Dive Services Supervisor Rob Robbins helps Mike on his first surface supply dive. (Photo courtesy of Annamarie Pasqualone)
Mike waits for the okay to plunge. (Photo courtesy of Stephanie Guida)
Getting used to it
There are a couple of things to get used to with surface supply diving. First, because of the helmet, you have to turn your entire body to look around. You sort of have tunnel vision. Second, you have a tether, connecting tube, that you are pulling along. Somebody on the surface needs to keep putting that in the water. If they forget, you feel a tug when you try to swim. Finally, the other difficult part for me is equalizing your ears. Let me explain.
Have you ever dove to the bottom of a swimming pool or gone up in an airplane? If so, you've probably felt a strange pressure in your ears. What you're feeling is a difference in the forces acting on your ear drum. In the pool or for divers, the deeper you go, the more water there is pressing in on your ear drum. The trick is to let air up behind your ear drum to press back against the water. People do this by wiggling their jaw, chewing gum, or pinching their nose and gently exhaling. This last option is the most popular and requires pinching your nose. You can do this when you just have a SCUBA mask on, but not with the helmet. There is a little device in the helmet you can use to block your nose, but it takes some practice. well, at least, it's going to take me some practice.
Mike descending on his first surface supply dive. (Photo courtesy of Steve Rupp)
Mike on his first surface supply dive under the ice. (Photo courtesy of Steve Rupp)
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Summary
Although surface supply is a new challenge for me, it's definitely worth learning. I love learning new things. That's the great part about being here. There are so many patient and helpful teachers who are willing to help me get better at diving, helping in the lab, and being a better scientist.