A Salutary Experience 7 March 2011

plunge

Orcombe Point


Wild swimming is all jolly fine - and who wouldn't want to take the plunge on the beach above? - until something goes wrong. In what follows I nearly went wrong, only avoiding disaster by the skin of my teeth and through sheer luck.

7th March 2011 was a great day; high pressure, nearly cloudless with an easterly breeze. Out of the wind it was warm. Back home, daffs and tulips were out. Water temperature 8.3° C. There was quite a big spring tide, just two weeks before the equinox. I swam in the middle of the ebb, about noon. [High water ca. 0800 hrs 3.8m; low water ca. 1400 hrs 0.4m] The Rule of Twelfths states that the rise or fall of tide will alter by approximately 1/12th of the total in the first hour, 2/12ths in the second, 3/12ths in each of the third and fourth hours, then reduce to 2/12ths in the fifth and 1/12th in the final hour. So the least amount of water is shifting at the start and finish of ebb and flood and increases to a maximum in the middle.

It was choppy rather than rough, with two to three foot high waves coming ashore. The tide was already more than half out. It seemed to take an age to get deep enough to swim so I ducked down well before I was even waist deep. For the first ten or twenty strokes I could still feel the bottom with my hands as I swam. “Right,” I thought, “let's get cracking. Fifty strokes for France.” After about 30 strokes I decided to check for depth only to find I could no longer touch the bottom. I'm about 6ft., the depth was about 8ft. I turned around and headed back to shore, taking a bead on transit marks ashore but found, to my alarm, that I was still going backwards. France was on!

chart

The main channel from seawards into the Exe Estuary is marked by a line of buoys, indicated on the chart above starting with E. Exe, at bottom right of the image, and continuing with No.1, No.2, No.3 etc north-westerly. The local almanac states that the current in the main channel can run at up to 4½ knots. It was certainly hammering out on the day in question. An average swimmer - and I am only a very average swimmer - can expect to swim at about 2 knots. A really good swimmer might manage 3 knots for a short distance. Clearly, expecting to make headway against a 4 knot, or even a 2 knot current, is optimistic bordering on plain stupid. But then I had not anticipated any of this.

I am not sure exactly what happened next, apart from slipping effortlessly into panic mode, but I noticed that each wave gave considerable assistance towards the shore while immediately behind it was a corresponding but slightly greater tug away. I tried to make best use of the former while resisting as much as possible the latter. Somehow I was soon able to touch bottom again. Fortuna favet fatuis - on this occasion anyway.

So technically I was back in my depth and everything was hunky-dory. Or so I thought. The undertow was so strong that I was unable to remain standing in the same place while shoulder deep. Waves either broke over my head or lifted me off my feet and I was then carried backwards, further out of my depth, by the undertow as each the wave passed. Even when chest deep, progress towards the shore was extremely hard. What seemed to work best was leaning as far forward as possible, which was not very far at the outset on account of the depth of water, and ‘running’ with the feet while flailing my arms like a madman. [Well, here I am aren't I?] The result is a better definition of what it is to be “out of one's depth.” In adverse conditions I would say anything more than waist deep. One inadvertent mouth or lung-full of water when chest or shoulder deep would be seriously inconvenient!

Ironically, I had intended the swim to be an endurance trial for how long I could remain in the water before it got too cold for comfort and had planned to stay in for 10 minutes or so. As it was, I didn't get around to that as I was too freaked out and just wanted to get ashore, but it did mean that I had taken note of the time as I entered the water. I was immersed for just under 6 minutes. As far as the temperature was concerned I could have stayed in longer, but the exertion required to return to safety was enervating and I was pleased to get ashore to put it mildly! The cold endurance had to await another day.

The most important lesson learned was the absolute need for planning - not during, not after, but before! My rules gave me a false sense of security. I had no plan what to do if things went wrong. In cold water there is very little time in which to think effectively. There is not only fatigue with which to contend but the cold renders the muscles less responsive and efficient. And it is the wrong place to start planning. I don't know what I would have done had I not been extremely lucky, but having thought about it a lot since, I now have a plan of sorts should anything similar happen again. I should have had one before entering the water.

icon I was about where the symbol at right is on the chart above when I found myself out of my depth. The deep water channel, indicated by the buoys, is presumably scoured from the leveller surrounding sandbanks and beach by the flow of water, but I was not aware exactly where it started nor how steeply sloping its sides, but I assume I must have drifted into it. The exact spot I chose to swim was a narrow corridor of sand unimpeded by rocks ahead but bounded on each side by rocky promontories. These must have somewhat reduce the current along the shoreline but once beyond their shelter the full force of the stream was encountered. Having failed to make a conscious note of this at the time, I think I must strayed unwittingly into a ‘danger’ zone. It is also worth remembering that the exact conformation and depth of such channels will probably change considerably over time and should either be reviewed regularly or due allowance made for their not being the same as previously.

Had I not been lucky what should I have done? What I actually did was instinctively swim as directly as I could for the shore. If I had not regained my depth this was probably the wrong strategy ‘long term’ i.e. for the next 5 or so minutes when I could reasonably have expected to swim effectively. Swimming westwards would have been an even worse choice as not only even more directly against the current but also towards a small ‘bay’ from whose shore the water eddied at an accelerated speed seawards. By the same token, eastwards there might have been a slackening of current, even, being really optimistic, an eddy inshore. (Straight Point, 200 ms or so off the chart, forms another large bay, Sandy Bay, which is comparatively sheltered and may eddy.)

So, all in all I failed on “know your coast” as well with “take care with the tide.” Nautical charts are a good place to start. Another place is a nautical almanac which have a wealth of information about tides, currents, hazards etc but bear in mind they are prepared primarily for people in boats and concentrate on navigable waters. Your public library should have a current almanac apart from the fact that our poxy politicians seem hell-bent on closing libraries. Make doubly-sure the almanac is the current one. They are published annually and the data contained, especially for time and height of tide, alters yearly. If you plan to swim in un-navigable waters you will need to rely on your own interpretation of data from sea charts.

swimmer

Me duce, tutus non eris.

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© 2018 Duncan Linklater