Pages

Wednesday, March 05, 2008

Eddy lines, boils and whirlpools in the Dorus Mor


16:08:18


16:08:20 Something seems to be stirring ahead...


16:08:22 ...thankfully it's only a tiddler!


These photos were taken within the Dorus Mor before we cleared Craignish Point. We were travelling at 12km/hour which equates at 6 knots neaps as marked on the chart. I found myself progressing along an eddy line between a large, upwelling smooth boil on my right and a more disturbed area on the left. As you can see from the small blue segment on the GPS track, this corresponded with a sudden (involuntary) change in direction.

All of a sudden a small whirlpool appeared at the interface and within 2 seconds sucked air down to at least 6 feet below the surface of the crystal clear water. I dropped the camera and snatched my paddle out of the water to perform a reassuring air brace (as one does). Over the next minute I saw another five, near identical, whirlpools along the eddyline. Many years ago from a yacht, I saw about ten similar little whirlpools along another eddy line which forms nearer the Craignish peninsula.

If there had been any wind I would not have seen them, the Dorus would have been a very lively place and I would not have been doing any air bracing!

Our maximum speed was well thorough the Dorus Mor when we reached 16 to 19 km/hr where our track went northwards near where the chart mentions tide rips. We did need to paddle quite hard to break out of the race, otherwise we might have ended up heading for the Corryvreckan. We started paddling north just after we met the whirlpools. You can get some idea of the flow by the large arc of our track.

12/02/2008

2 comments:

  1. How very interesting, 6 full feet below the surface! Not tiddlers to me.
    Do you think it had something to do with the depth of the seabed at the place, Douglas?

    ReplyDelete
  2. Wenley, this was at the narrowest part of the Dorus Mor and great boils of water were coming up from the bottom as it moved west at 12km per hour. These boils bulge up up above the level of the surrounding water.

    At the edge of this particular boil there was a counter eddy and these two bodies of water were sliding past one another. The whirlpools were forming at the interface.

    Any bigger and it could have been scary!

    ReplyDelete