Monday, July 30, 2012

My Yacht

I have not blogged during the last week because I was in France where I went to launch my yacht following a refit.  Although some of you readers may keep yours in Cannes or Monaco, mine is in Baden in southern Brittany.

Although I forgot to take my Abu Dhabi Sailing Club burgee I nevertheless managed to get my yacht properly fitted out and ready for a seasonal launch.  I accomplished the mise à l’eau using a borrowed trailer and with a couple of friends we got it down the slipway unscathed and launched it.  No champagne, but it was gleaming with a new paint job and it was a proud moment.  I provisioned it for the initial cruise by stowing 2 sandwiches and a bottle of water in one of the little open lockers under the forward seat/thwart/mast support.

Unfortunately a stationary high pressure system provided lovely, cloudless skies with wind that was coquettishly fickle, ranging from none to occasional tantalizing breaths that were more exasperated sighs than real breezes.   And the tides in the Golfe du Morbihan are not for wimps and more than once I was making going backward, waiting for enough breeze to make some headway.

But I enjoyed a nice shakedown cruise and everything worked out.  I made only one obvious mistake – noting a strange vibration coming from the dagger board, I realized I had inserted it backwards.  Luckily my crew was a first time sailor (photo below) and he didn’t realize just how stupid this was - I didn’t bother to remedy his ignorance.

My yacht is a classic French vessel belonging to an internationally recognized class –  a Vaurien
(Stock photo - not my yacht).
Designed by Jean-Jacques Herbulot, the first one was seen at the Paris Boat Show in 1952, built of plywood.  Herbulot is a French sailing legend, who competed in 4 Olympics and designed 70 boats (at least that is all his widow could remember when asked).  Almost every French sailor will have sailed one at some point. 

Over 36,000 have been built.  It was commissioned by Philippe Viannay, the founder of the famous Glenans sailing school, who wanted an affordable dinghy for his school - which would be the same price as 2 bicycles. The name was said to be inspired by the name of a dog belonging to Viannay and literally means “worth nothing” (vaut rien) but is usually translated “good-for-nothing” or “rascal”. 

My yacht is kept in a friend’s boatyard and I was lucky to be able to speak with Eric, one of his master woodworking craftsman who owns 3 Vauriens, including a wooden one.  He took a few minutes off from his work to give me some tips on dealing with the complexities of rigging my yacht’s sophisticated mainsheet system which starts with passing one end through a hole in the port side of the transom and knotting it  – then passing the running end through the block at the end of the boom and finally through a second block on the starboard side of the transom and then into the helmsman's hand.  This is direct sail control – no fussy traveller, jamcleats or other unnecessary paraphernalia to interfere between the yacthsman and his mainsail.  The jib sheets dispense with blocks altogether and rely on simple fairleads leading into jam cleats.   (A heads-up to the Harken marketing department - concentrate your efforts elsewhere.) 
The mainsheet system can be seen in this photo of the above-mentioned first-time sailor - an action shot I took for his mother to show how valiantly he mastered sailing on his first day out  - and never mind the limp mainsheet and total lack of any wake or ripple on the water.

Saturday, July 21, 2012

Switching Boats

The last 2 weekends I have not raced my Laser but have taken out a Kestrel, a two-handed dinghy - both because I have meaning to learn how to helm a 2 handed dinghy and also because of the very high heat/humidity that totally exhausted me on the Laser the weekend before.

When I sailed the Laser, I was far from very good, but at least I had gotten to the point where I was less worried about the basics and could concentrate on trying to improve. Getting used to a new boat with two sails plus spinnaker, lots of fiddly controls and another person aboard definitely took me out of my (relative) comfort zone.

For both weekends I prevailed on a more experienced Kestrel helm to crew for me and let me helm, with him available to give me tips.  It was much appreciated and by the end of the second weekend my comfort level, while still in the less than really comfortable zone, was much better.

Concerning the heat issue, I am now convinced that I had trouble mainly due to the high humidity which is usually a factor mainly in August but which was quite high recently.  The proof is that in my first weekend out on the Kestrel, the humidity was still quite high and that, coupled with my stress in trying to manage the new boat, forced me to retire before finishing the first race.  Yesterday the humidity was not high (I can always tell it is high when I step out of an air-conditioned building and my glasses immediately fog up completely) and I finished 2 races in the Kestrel without being overly tired at the end.

Back to learning the Kestrel, I enjoy it a lot.  First, it is really nice not worry about the main sheet lassoing the transom during gybes.  On the other hand, I did capsize once during a gybe because I forgot to straighten the tiller and we just kept coming around into a perfectly executed dry capsize for my experienced crew who saw exactly what was happening and managed to be over the side and onto the centerboard before the mast touched the water- I was in the water of course.  But that lesson was quickly learned and I doubt I will soon make that mistake which is so basic and easy to avoid.

Learning how to trim the headsail and mainsail and coordinating tacks and gybes is fun and quite different from a Laser.

And thinking about how best to work as a team with the crew takes concentration. As is true for most relationships, good communication is the key.

So I enjoy it, but this afternoon I took the Laser out for a spin just to keep in touch.  I really enjoy the little boat - somehow you feel closer to the wind and water.

Wednesday, July 18, 2012

Expatriate Sailors

I was reflecting the other day on how international our sailing club is -  we have about 20 regular sailors and they hail from 
  • Argentina
  • Australia
  • Barbados
  • Canada
  • Denmark
  • England
  • Germany
  • Greece
  • Ireland
  • Italy
  • Lebanon
  • Netherlands
  • New Zealand
  • Scotland
  • South Africa
  • Sweden
  • USA 
 I like that.

Expatriates are really almost a separate nationality - no longer the same as they were in their passport countries, expatriates usually have more in common with other expatriates of all sorts than with their original compatriots.  I have lived most of my adult life as an expatriate and have been blessed for it.  Of course expatriate lifestyles have negatives as well as positives, but no one can deny the available richness that is an integral part of it.  I say "available" because some expatriates choke off this invigorating oxygen by closing themselves in, but that is their problem.

It is true that the older I get the more some of the old hometown tugs at heartstrings - no doubt due in no small part to sentimental memories that are more yearnings than real memories.  But if I had it to do over again I would choose the expat lifestyle again in a heartbeat.

Saturday, July 14, 2012

Helpful Cavities

Exploring the problems in sailboats approaching 60 knots (I can dream) we saw how cavitation is a real problem.

But apparently this phenomenon, when pushed to the extreme can be a real boon - at least for some objects like torpedoes and maybe for boats.  I refer to supercavitation.

As you will remember, cavitation is liquid turning into vapor (bubbles) due to a pressure differential - for instance bubbles forming on the low pressure side of a foil when that reduced pressure goes below water's vapor pressure. Huge drag ensues.

In supercavitation you turn a real drag into a huge boost by "simply" making the bubble large enough to encapsulate the entire object, thus drastically the amount of wetted surface and drag.  The trick to doing this is to inject additional gas into the bubble until it gets large enough.

The photo above is from the University of Minnesota "cavitation and bubbly flows research group" (as Dave Barry would say, a great name for a rock band).  It shows axisymmetric ventilated supercavitation with ventilation increasing and cavitation index decreasing from top to bottom, but I am sure I didnt have to tell you that.

At any rate, the military superpowers have long been interested in supercavitation as a way of making torpedos and other underwater projectiles go very fast. The Russians made the Shkval VA-111 torpedo which allegedly goes 500 km/h.  DARPA has the Underwater Express program which envisions a submarine at 100 knots and according to some sources a one-quarter size model has already been tested off Rhode Island.   Tillerman, have you noticed any unusual currents lately?

And now a private company claims to have a developed a supercavitating stealth watercraft.

And finally if you have a hankering to build one yourself, Scientific American can give you some hints, Although they do mention that it will require "a deep understanding of the fluid mechanics and hydrodynamics of this novel flow regime" this shouldn't be a problem for my readers (note I did not include myself).

Tuesday, July 10, 2012

Heat Saps

Sap.  In plants it is life giving and invigorating - how curious it is that the same word describes what heat and humidity can do to the energy of a no longer quite so young Laser sailor.

Summer in Abu Dhabi is not the exactly the same as in Europe and while the worst is in August, last weekend was tough with temperature of 45 C (113 F) and a high dose of humidity, making it feel much worse. Our club sails every Friday year round and that is great most of the time.

But, I have to admit the heat took a toll on me last Friday.  We sailed 2 races and I did well in the first one, but it tired me out.  I had made a big mistake, wearing hiking tights because I thought the wind would be strong and the inserts behind my thighs would make me less tired. But the wind was only 10-12 knots and the extra insulation from the hiking suit more than offset any positive effect.  Between races I floated next to my boat but the water is warm and refreshes very little.

I considered calling it a day after the first race, but went ahead and sailed the second race, doing poorly. And sailing back after the race I could have taken it easy, but I couldnt resist trying to catch a boat ahead and went into semi-race mode. Testosterone thinking.

I had been careful to stay hydrated during the afternoon with both water and sports drink, but by the time I got back to the slipway, having caught the other returning boat, I was running on fumes.

Pulling the Laser up the slipway took my last reserves and I had to lie down on the hull a few minutes - I was feeling lightheaded.  I de-rigged slowly and everything eventually sorted itself out once I got in the bar with a cold cider.

But, I will be sailing a two-hander over the next couple of months in order to ease up a bit on the physical effort in the heat. Plus I have been meaning to improve my acquaintance with a stayed mast, jibs and spinnakers and this will be a good time to do so. 

Friday, July 6, 2012

Harmful Cavities

Recently we looked at human-powered submarine races.  Today we take a look at another water craft which is certainly a sailboat since it floats and has a wing sail and generally has the elements one would expect to find.  But it doesn't exactly fit what I think of as a sailboat.

In the sailing world I am used to, masts are at 90 degrees to the hull and the water (well, sometimes my Laser mast is parallel with the water).  Not so on this boat.

And in the sailing world I know, it is a given that the hull is in a direct line with whatever direction the boat is headed. Not so on this boat - which has the hull (or, as they refer to it, the main fuselage) and beam at 20 degrees to the actual direction of travel.

All this in an attempt to beat the current world speed sailing record of 55.65 knots held by a windsurfer (assuming the windsurfers don't do so first).

This boat is actually the second (and hopefully improved) version of the original prototype which reached 52 knots.   Check it out here - the Sail Rocket.

Which brings us to cavitation - a problem usually associated with propellers.  Apparently it is also a major problem for the foils on boats approaching 60 knots when water turns to vapour due to the very low pressure on one side of the foil, creating a cavity or bubble which produces lots of drag and loss of stability.  Another way of explaining why that matters -  the pressure exerted on a surface by water is about 14 psi and the pressure exerted by vapour is almost zero,  a difference of nearly 10 tons per square meter.  Ouch.  The cure for such cavities is not a good dentist, but to find a way to "ventilate" - by getting air at atmospheric pressure into the cavities created by the cavitation and eliminating the drag-inducing pressure difference.

The good news is that since cavitation is not a big issue until around 60 knots, it is one less worry for me on my Laser.

Thursday, July 5, 2012

Submarine Races

We sailors rightfully take pride and inspiration from the fact that we navigate our craft using only nature - the wind and our own physical efforts - and we routinely disdain stinkpots and other forms of practical locomotion (except of course when we need them, but let's not quibble).

But, even our noble sport might be disdained by another set of sportsmen who use only their own muscle power to race a water craft - I refer to human-powered submarine races.  Maybe this sport is not quite as developed as ours, but don't tell that to the engineering students who compete every year. 

The rules are simple - "teams must design, build and race flooded submarines piloted by one or two scuba divers, who must be fully enclosed within the hull of the machine. All propulsion power must be provided by the diver during the race (i.e. no energy storage devices such as flywheels or batteries are allowed), but otherwise the design rules are open to whatever innovation teams decide to use." 

I guess David Bushnell and his fellow Turtle crew members could claim bragging rights as having competed in combat conditions without scuba equipment.

Long dominated by the Americans who have held the International Submarine Races since 1989,  the first European championship event was recently held at Gosport where a Canadian team from École de Technologie Supérieure streaked to a world record in their submarine Omer 8 over a 13 meter section of the course where they were clocked at 7.03 knots. (I assume we can rely on this report, although it does not say whether the official timer was Rolex, IWC Schafhaussen or other). 

You can see a ten year history of the ISR Championships with some videos of the submarines streaking along, albeit not quite as fast as the above mentioned current world record. 

And for you lucky US readers, please reserve your calendars for June 24-28, 2013 when the ISR championships will be held once again in Bethseda, Maryland.

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