2000-01 Current Thinking

By Karl Shreeves


Bet Hillary and Krakauer felt like this a hundred times on Everest,” I said to myself, hanging suspended over the void, my well-being—life perhaps—entrusted entirely to a single rope. It seemed adequate before, but now looked all too thin. Of course, Hillary and Krakauer hung over a vertical drop risking a terminal velocity plummet to a quick demise. I hung over a horizontal drop by a short jonline in raging current, flapping like a beleaguered pennant. With an hour of decompression to go, “falling” risked drifting for days with seagulls pecking my scalp until either I lucked out or died if the boat didn’t find me right off. Or, it risked blowing off my deco and pretzeling me into a wheelchair. Better not “fall.” Extreme or Tech Divers can enter a contest at Scuba.com.

I hate decompressing in current. One of my tek diving mentors, Billy Deans, told me, “The problem with diving in strong current is that it exploits every weakness,” and he had it nailed. Yet in some of the top tek spots, the water rushes almost without exception, making current diving SOP. You love the dive, but you don’t gotta love the current. You do have to deal with it.

Dealing With It
While we all like dives that blow us away, we don’t want to get blown away on a dive. With typical current diving procedure (in tek diving this means a deep wreck 99.999999999 percent of the time), you bail into the water fully rigged and grab the swimline, which is a line from the entry area to the anchorline, which itself is presumably snagged in the wreck (if not, you’re going to deco for an hour for the privilege of looking at deep sand. Been there, done that.). You pull hand-over-fist along the swimline (a.k.a. tagline) to the anchorline, and then down the anchorline to the bottom where there’s not much current, especially if you stay in the lee of the wreck or reef.

So far, that doesn’t sound much different from recreational diving in a current, and in fact it’s not. The primary difference during the descent is that if the flow’s really ripping, you loosely wrap your jonline around the anchorline so you don’t blow off. (A jonline is a short line clipped to your harness at one end with a hook, loop or clip at the other to secure it to the anchorline. It has more uses on the way up. Hold your horses; we’re getting there.) Presumably, when the current is that strong, recreational divers head elsewhere. And you’ll notice there’s no reference to hang bars or suspended tanks like recreational divers use—that’s because; a) if you don’t return to the anchorline for some reason, you better have your deco tanks with you; and b) when the current’s strong, a diver hanging on a suspended line gets blown to the surface. That’s why you deco on the anchorline.

The Ascent
Your buddy gives you the thumbs up. Being smart, you returned to the anchorline well ahead of ascent time (so you have time to look for it). To keep from sailing away in the flow, you loop your jonline on if the it’s really rushing. You reach your first deco stop—say 70 feet—and the 19 other divers on the charter get there within five minutes of you, putting 20 people in the same spot at the same time.

At this point, the seasoned tekkers pull out their extra-long jonlines—some 15 feet or so long—and cinch them down on the anchorline. Then they drift out into the current, maintaining depth buoyancy control and angling their bodies against the flow, tethered like kites on their lines away from the huddled mass of elbows and faces jammed into faces and groins. Rookies. After each stop, the seasoned gang haul themselves back to the anchorline, loosen their jonlines and move up 10 feet for the next.

Finish your last hang, surface and follow the swimline aft, and hang onto the trail line until it’s your turn to get aboard. It all sounds easy, except that if there’s a sea running (almost always), the anchorline yanks you up and down (unless you’re on a long jonline), and it takes continuous effort to hold in place against the current (even with the jonline). Sometimes you’re more tired from the deco than the dive (it gets easier with practice).

Blown Away
Of course, things don’t always go as planned. You can’t find the anchorline, or you lose it and away you go, blown away in the current. Told you to hook on your jonline, but if you and the dive boat prepare for this, you’re not necessarily SOL.

First you send up your huge, tall, bright yellow liftbag via line and reel. There are serveral XS Scuba SMB (Surface Marker Buoy) and are available at Scuba.com. Hopefully the first mate keeps watch aft and says, “Okay, there’s another one we have to chase.” You do your decompression drifting under your bag, reeling up line as you ascend. You’ll be a good ways down current when you surface, but directly down current from the boat. To make sure they spot you easily, you deploy your safety sausage (which is even taller than your liftbag) and flash the captain with your signal mirror. Failing all that, open the housing of your EPIRB (Emergency Position Indicating Radio Beacon), trip it and hopefully the Coast Guard wings to your rescue. Assuming you’re in U.S. waters. Assuming it works. Hmmm.

There are variations, of course. For instance, in many parts of the Northeast U.S., you almost never return to the anchorline. Instead you send up your liftbag (big one—100 lbs+) on some serious rope, tie off on the wreck and ascend along the rope doing your deco/jonline thing. Surface, cut the line (use biodegradable rope) and swim to the boat (you’ll be up current from it).

An Easier Way
Being a certified WIMP (Why Inflict More Pain?), I believe that hanging in a current sucks, and it’s better to decompress without a current. But how do you turn off a current?

You don’t (duh). Instead, dive teams coordinate to return to the anchorline at about the same time. You deal with the current as per above, but when everyone reaches a specific depth or shallower and all divers are accounted for, the boat casts loose and drifts, all the submerged divers going along. Hanging adrift is effectively hanging with no current; everyone chills out. Not only is it much more relaxing and avoids the concern with getting “blown away,” but it’s easier for support divers to move about, make sure you have plenty of gas, take unneeded gear, etc. Even a two hour deco seems to go by faster.

Local Style
Although it would be great if you could, you can’t drift hang in all locations. Logistics can complicate matters, such as if the boat might drift into a shipping lane, or if relocating the dive site for a second dive is almost an impossibility. Because of this, current procedures during tek dives vary considerably, depending on where you are. If you’re not familiar with the local practice, get an experienced local tekker to give you a run down about the area’s current thinking.