Any significant volume of water pouring down those steep sluices from underneath the gates would be expected to produce a large hydraulic with a strong reversal current. Presumably, the two victims got recirculated repeatedly. Too bad the gates could not have been closed more quickly.
I suspect most boaters with whitewater experience would have recognized the boil line that marks the boundary between the downstream current and the reversal, and stayed well away from it. But it sounds like these individuals may have had only flat water experience.
If the flow through the gates had been increased when the pair were in the immediate vicinity, the reversal current could have suddenly increased and the boil line moved further down stream.
@pblanc Just to comment on one thing that makes me a little crazy from folks who only do WW - and you are not the only I have heard this from. Long boaters and flat water boaters are NOT necessarily the same thing. Flat means water that is flat, or relatively so. That is not the case when dealing with waves and haystacks over your head off of points at low tide or in tidal races, or in bigger surf, or getting caught out in a squall of the same, or in wind at a high enough speed to push big waves. And dealing with this for distances more like a half mile to a mile if things catch you rather than getting to a nearby shore.
That rant done, yes big water paddlers often are not trained as well as WW people to see then patterns in moving water or be aware of its behavior thru narrower spaces. The closest would be people who have worked in tidal races, but that is probably only a smallish percentage of all sea kayakers. Partly because the really strong ones only exist in certain places, like the upper northeast and northwest.
Sure, different challenges exist. But pour overs creating strong hydraulics are not common features for ocean paddlers. Most whitewater boaters of experience have been stuck in a hydraulic a few times and have likely been recirculated at least once or twice and found the experience memorable. And many have spent hours scouting hundreds, if not thousands of rapids, scrutinizing them intently for “boat traps” like hydraulics and big holes. The eye becomes trained.
Sometimes a killer hole, a recirculating eddy, or lethal hydraulic might appear quite benign. Many have died after running a weir and getting caught in the reversal because it looked “easy”. There is a hole at the top of Woodall Shoals rapid on section IV of the Chattooga River that has killed dozens which can look quite benign to even whitewater paddlers of moderate experience.
I have seen kayakers casually attempting to enter their boats in the tail end of a recirculating eddy below a low-head dam who found that they had drifted back into the strong reversal current by the time they got their spray skirt on, and have to paddle ferociously or have a rope thrown to them to escape the pull.
The point is that this pair clearly did not recognize the potential of a reversal current or they would not have ventured anywhere near to it.
in general I avoid paddling in, around, or over manmade structures, that even includes artificial ww courses! I rarely “play” under bridges, since there is often manmade debri there as well.
One of my favorite runs has it’s share of rebar, chunks of concrete. and other debri but I’m pretty cognizant of where it is (scouting at low flow) and work to avoid it. Yes, I’ve run a few dams and even purposefuly surfed in spillway outflow. So I have made exceptions when it suited me. I think in general, folks underestimate the dangers of manmade structures- be it a cattle fence, a low head dam, a spillway hole or backwash, and often even breached dams have unseen debri.
I think each of us needs to be prepared (skillset and gearwise) for whatever environment we choose to paddle in. “Flatwater” can be anything but flat.
Ocean and Great Lake paddlers got way bigger kahunas than I do. That water is deep and you can be a long way from shore. Then you throw in currents , tides, wind, water temps, and ocean critters and there is a lot to consider.
As far as woodall shoals (chattooga) and the L (big south fork): know the water levels, be on your line, and punch drops real fast and hard (or in the modern age boof) or you just carry around that stuff. Understand that mistakes can have serious consequences. It’s your *ss on the line so you make the decision. “Stuff” does happen.
As far as certification, I am certifiable, just not at a very high level. Certification in general is a good starting point but not the end all be all. This discussion reminds me it’s time for me to again renew my first-aid/cpr and that I have some pretty huge holes in my own game that need to be filled (I struggle with rolling and hand of God).
Interestingly when the Appalachian Mountain Club started running trips out of Knubble Bay ( inbetween two sizeable powerful tidal races) the leaders were all out of Boston AMC Whitewater committee.
I am pretty good at dealing with tidal whirlpools and eddies that constantly change but ask Pete about failure to hug a rootwad on the Current. He helped me out from my forgetfulness.
So while some whitewater skills are handy for long boaters on the ocean it does not make us skilled river runners… And embarrasingly I am a Level 3 ACA instructor. Freestyle… And about a level one student on the river.
These guys were not big water paddlers or seakayakers, i think most experienced ocean paddlers who do rock gardens and tide races would have known the signs meant there was a reversal current and hydraulic at the base of the dam. Most of the people I paddle with can recognize details on the surface of the water that tell a story of current and where you want to be and where you don’t want to be. The victim’ training and pictures show two flat water, inland boaters. Unfortunately owning a seakayak or a vanilla touring SINK does not give you moving water skills by osmosis. Anyone who has ever done any training near a dam has been told of the dangers. Its a sad lesson for people on that river to learn. In hawaii they post very severe warning signs, some say how many people have drowned at a particular spot on the coast, and some show cartoon images of how you will be bashed by the rocks and waves and drown. Maybe the signage in Iowa should be more explicit.
@qajaqman said:
In the article I posted they were downstream and got sucked upstream.
That seems more likely to me - the reversal on the downstream side of a dam that big must be pretty powerful, and why would anyone paddle close to the gates on the upstream side.
In ACA parlance, “L” usually simply denotes “level”. Here are the baseline physical requirements and instructional expertise expected of an “ACA Level 2: Essentials of Kayak Touring” Instructor Candidate:
As you can see, at this particular level, what is expected of the instructor is some mastery of basic flat water strokes, rescue and re-entry techniques, and flat water safety issues and hazards, although weather and tide conditions, signaling devices, boat traffic issues, charts, and float plans are also part of the curriculum.
But basically nothing mentioned about dynamic moving water hazards.
It is not until “ACA Level 4: Coastal Kayaking” that the following skills are required:
kayak roll
Negotiate Moderate Wind & Sea Conditions
Paddling comfort in moderate seas
Ability to paddle in a head sea / beam sea / quartering sea / following sea
Ability to turn up and down wind efficiently
Ability to hold position
Negotiate Moderate Surf
Launch & land forward
Launch & land backward
Surf, broach and side surf
Negotiate Moderate Current
Establish ferry angle (forward & reverse)
Control peeling out / eddy turns
Kayak Tripping:
Day Trips: show evidence of at least three or more day trips of at least 12-15 nautical miles in various conditions
Multi Day Trips: Show evidence of at least one multi-day journey involving overnight camping
I guess l did not recall what L means. That said, Pblanc explanation doesn’t sound like someone who would have yet experienced a broad,mix of more challenging big, or moving, water conditions.
