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Boldly going: Exploring the ocean depths in human-occupied vehicles

Drs Jon Copley and Verity Nye, and Professor Paul Tyler MBE, talk about their experiences of diving in the deep ocean.
JON COPLEY: As well as the autonomous robotic vehicles that we’ve seen for ocean exploration, we have human-occupied vehicles – manned submersibles that can take us to the deep ocean environment we’re trying to understand. The three of us have all dived in these submersibles in our research. Paul’s made many dives over the years. But to someone who’s never had that experience, what are some of the impressions of visiting the ocean floor?
PROFESSOR EMERITUS PAUL TYLER: I think the first impression is your eyes are different to watching things on a screen. So when you’re down there, you look out through the sub porthole, or you look out through the front of the Johnson Sea Link submersible, and you get a three-dimensional image very clearly. That is, I think, the main difference from using an ROV that we use nowadays. A few years ago, I dived in Alvin, to a place called Tube Worm Pillar, which is a 50 metre high pillar covered in the bright red plumes of tube worms. And you could just see it out of the portholes.
And the pilot just said to me, “This is such a sight that you’ve just got to see it through the pilot’s porthole.” which is a much bigger porthole. And so the two scientists on board got an opportunity, just for a few minutes, to look out the pilot’s porthole. And I have to say it was the most lovely, the most fantastic biological sight, I’d ever seen in my life, and have ever seen in my life. When they’re using the manipulator arm, you really feel it’s your arm doing things. And you’re thinking as though you’re picking up something on the table, and that sort of thing.
Where it doesn’t feel quite the same with a ROV when you’re doing that, partly because you’re not intimately involved, whereas you are in the sub. And you really feel like you’re actually doing it there and then. There are lots of downsides. The amount of time you get on the seabed is limited. It takes time to get to and from– there are many more safety issues than using an ROV. But there’s something, as a deep sea biologist, you have to do at least one dive, just to see what the seabed was like and have your nose up to it, and say yes, I’ve been there.
JON COPLEY: So, Verity, you’ve just made your first dive as a deep sea biologist. What’s the most lasting memory that you carry from that? DR.
VERITY NYE: Well, I tried to remember as much of it as possible, and just having a deep-sea vent there, with the fluid gushing out, right in front of my face, and seeing shimmering water, and animals that we discovered a few years ago there, living where they are naturally. It’s just amazing.
PAUL TYLER: Verity, what did you do to prepare for your dive?
VERITY NYE: Well, I did quite a bit of planning in terms of the actual dive plan, to figure out what we were going to do on the dive and really think through in advance how I wanted the dive to go and progress. But other than that, not a lot. I just kind of watched other people get ready for their dive, so I knew what the process would be. Had a good night’s sleep the night before, and didn’t drink anything in the morning. So we had discussions a couple of days before that dive, to try and see where we are– it was quite near the beginning of the cruise– and what people would want to get out of that dive.
But basically, you’re putting that plan together. It’s your dive, so you’re in control of what you want to get out of it for as many different people and disciplines as possible. And I think that’s one of the things I found hardest down there. You’re so tight on time, and you have this big shopping list of things to get through. Got to make sure that the pilot and co-pilot know where they’re going and how to get there.
JON COPLEY: What about some of the limitations, though, of manned vehicles, compared with ROV operators. We’re lucky; we now have both sets of tools to work together. What are some of the things that ROVs can do that manned subs can’t?
PAUL TYLER: There’s a time limitation. If it’s deep, it’s even more of a time limitation. And if you find something particularly interesting, you can communicate with the surface, but it’s not that easy. If you’re using a ROV, you’re going to use it 24 hours a day. And so you continue use it. If there’s something that’s kind of interesting, you can actually go and call on someone on the ship to come to the ROV van and say, we weren’t expecting this. This is your area of expertise. Do you want a sample? Do you want a video? Do you want– you know. And you can go ahead and do that sort of thing.
With the submersible, the people down there are on their own and the ship doesn’t get anything until it gets back. First thing that comes out of sub when it’s back, (it is) the videos to look at them. Whereas with the ROV, you’ve instantaneous access. And it comes back to something we were discussing earlier on– we now have the ability to transmit images from the sea floor to someone’s laptop computer instantaneously, or within two seconds, through satellites, and that engages the public, as well as scientists. So, I have to admit, I’m a ROV person now.
VERITY NYE: Yeah. What about things like manoeuvrability? Because I know in the summer you had some issues with the Shinkai (manned submersible), didn’t you?
JON COPLEY: Well, manned submersibles are a lot bigger than ROVs, and so they’re improving in manoeuvrability, but I think at the moment, ROVs have the edge. We can control them so precisely. And then we can carry out very detailed surveying and mapping tasks that you couldn’t with a manned sub. And you can get them into tighter places, as well, without hitting anything. So there are advantages there. It’s interesting. Recently, we’ve used ROVs a lot in our work, and really got a huge amount out of doing that. And having now gone back to manned submersibles, after a bit of a break, I still think you do get something extra from the experience. And it’s worth having both as options.
PAUL TYLER: Oh, yes! I have no problem with that at all. But I think in terms of maximising output– with a ship time, you might have waited two, three years for, and might not get any in the future. You want to maximise everything. Crews’ participation is bigger, and essentially the ROV is the way forward, I think. Though I do hope we keep some manned submersibles, because, you’re right, it is– there’s something special about using a manned submersible. In a sub, decision making has to be bordering on instantaneous. Whereas with the ROV, you can just say to the pilot “Park it.” And you can sit and spend 10 minutes, quarter an hour, half an hour, making decisions, which is lost time–
PAUL TYLER: –when you’re in a sub.
VERITY NYE: And I think that’s one of the things that we talked about when I came back, as well. That although you don’t have as much time, you can be as productive, because you have to maximise what you get out of that time, so you don’t waste any moments down there. And I think you’re better organised, as well. And although in some ways it’s a disadvantage not to have that communication with other scientists, you don’t have that distraction either. You’ve got the focus, so you just stick to what you want to get done.
PAUL TYLER: Oh, yes, that’s true. You’re in charge.
VERITY NYE: Yeah! I like being in charge!

Paul Tyler is a veteran of deep-sea dives in manned submersibles, with more than 20 years’ experience. In June 2013, Jon Copley became the first British person to dive beyond 5 km deep, aboard Japan’s Shinkai6500 submersible. And as an early-career researcher, Verity recently completed her first dive in a submersible.

In this video, all three scientists talk about what it is like to visit the alien world of the deep ocean, and why, in an age of remotely operated vehicles and autonomous underwater vehicles, actually sending humans to the ocean floor can still provide a useful perspective of the environments that we are exploring.

Remotely operated vehicles can work for longer periods on seafloor than manned submersibles, however, and their unique capabilities are also discussed further here.

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Exploring Our Ocean

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