Wednesday, June 6, 2012

Aerodynamic versus Hydrodynamic - A Lesson in Yacht Stability


The plan this weekend was to sail down to Brixham to catch the beginning of the heritage week celebrations and join in with the heritage regatta; however as usual things didn’t quite go to plan.

Due to work commitments I was unable to get away on the Friday to take part in the regatta starting on Saturday morning. Plan B was to leave on the 0530 tide on Saturday morning, but due to not getting home until Friday evening plan B was dead in the water. So onto plan C, depart as soon as there is sufficient water on Saturday afternoon and join in with the land based fun on Saturday evening.

My crew for the weekend was the Flint family, Darren, Helen, Laura and Samantha who are new to this sailing lark having just become the proud owners of an Eventide 26, which they are in the process of restoring. So for the Flint’s this weekend was a chance to get some sailing in as a family ready for the launch of their Eventide.      

Saturday afternoon came along and we sat waiting for the tide but it wasn’t until 1600 that we were able to slip our lines. The Axe was flowing extremely fast in the river mouth so with the Dolphin running flat out we crept out through the turbulent water only just making headway against the current. Once clear of the bar and out in the bay we had a good force 5 from the South East making the swell uncomfortable to say the least as we quickly crossed Seaton Bay under full sail. We rounded Beer Head and pushed on out for some sea room as the wind picked up from a 5 to a good 6, which going across what was now becoming a fair old sea tested the stomachs of a very fresh crew. By 1700 we were on course and heading towards Brixham with 23 miles to run. No problem if this holds we will be in Brixham well before 2100 and in good time for the fireworks.        

This was turning out to be the best sail for quite some time. We were on a broad reach flying full sail with the keels raised to three feet pushing an amazing 7.8 knots and more coming off the waves. We were surfing with a bone Epenetus’s teeth, accelerating at a tremendous rate with every wave. Pure adrenalin! Yes we were over canvassed and Epenetus was telling me so as the helm was getting heavy but wow what a buzz.    

Now a question, what happens when the aerodynamic force on the rig greatly exceeds the hydrodynamic force on the hull and the rudder can no longer compensate? Good question I hear you say and I’m pretty sure that even if you don’t know you can guess the answer. Your right the boat turns quickly across the wind and the inevitable happens doesn’t it, well it did and we broached; inevitable really given what we were doing. A strong gust and a big wave, the rudder didn’t answer so over we went. Sail, mast and even the spreaders in the water!

Now I know that I’ve got a strange sense of humour and maybe this was not the time, but it was a funny sight. As I clung onto the rubbing strake with my left hand I looked down across the cockpit to see Helen, who had been sitting on the lee side, with just her head and outstretched arms visible as the water cascaded over her shoulders, she had the most amazing open mouthed shocked expression on her face; Darren was doing an impersonation of a cartoon cat scrabbling to get away from the water but without any success and Laura and Samantha in a heap on the chart table. It was a very brief moment of comedy which came to a sudden end as I realised that the wash boards weren’t in and we were taking water, but not to worry because as fast as we had gone over we came up again. The whole thing was over in a matter of seconds.

We pulled some canvas down and carried on our way only in a somewhat slower and more responsible fashion. After an hour the rain came in and the wind eased but the sea state remained for a good while making life a little uncomfortable while we reflected on our lesson in yacht stability.

Arriving in Brixham just after 2100 we were greeted by Marcus and Rob the windows with hot coffee and pints of gin and tonic, now that’s what I call a welcome.



Drying out the boat in Brixham

Sunday was spent drying out Epenetus although to my amazement there wasn’t that much water, only four buckets full, proof as to how well the cockpit drains through the keel boxes. 

2 comments:

  1. Hi Roy, just posted about the Atlanta on 1001 boats Blog with a link to your blog - really interesting stuff, especially the comparison trip with Westerly - I've been from light displacement, to heavy and back again and am even more convinced of the sea worthy ness of light displacement - Max

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    Replies
    1. Max,

      Thanks for that, I'm glad you found it interesting.

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