PY Inland vs Sea

How about more clubs actually providing results to the RYA! Only 117 clubs actually returned real data through the PYS system.
Would be interesting to know how many data points come from each of the clubs.

Blimey, a day away from the PC and so much to respond to.

Tidal corrections are only any use if you are sailing with the tide. Take for instance the case where you sail with the tide and reach the far end of the course around HW then sail back with the tide. The slower boats make use of the favourable tide for longer and therefore gain from it. Portishead Cruising Club employ a correction for this in their Holms race. This correction however doesn't work in around the cans racing, where parts of the course are against the tide and other are with it. Typically faster boats perform better in tidal venues when racing around the cans while slower boats perform better in tidal venues when racing with the tide on long distance races.

Within the bounds of fast or slow handicap fleets there are always boats that seem to handle tide and waves better than others. The Albacore is a fine example, and even though it is hailed as a confined waters specialist the Graduate has always performed well on the sea even if the bulk of the fleet sails on rivers or very small reservoirs. On the flipside, fast boats such as 505s RS600, 700 & 800s, 49ers etc. are pretty grim on small ponds.

As for how to make the system better, AlexM is bang on. Get your clubs to put their data on PYS.

Not to mention the big differences you get if the two boats you are comparing have vastly different upwind/downwind profiles. In Cherubs it was good to have upwind with the tide (until the wind against tide kicked up too much chop at least) because we were so fast downwind. In Ics I suspect its probably the opposite, although I don't like to sail on salt water at the moment.

Originally posted by sargesail Slow boat: Boatspeed 4 knots.  Tide 2 Knots. 1NM against the tide = 30 minutes. With the tide = 12 minutes.  Race time: 42 minutes. FAst boat: Boatspeed 5 knots.  Tide 2 knots.  1Nm against the tide = 20 minutes!!! With the tide = 8.57 decimal minutes.  Race time 28.57 decimal  minutes. Sail it non-tidal - 2 NM for slow boat in 30 minutes.  The slow boat is 12 minutes (40%) slower in the tide!  2NM for the fast boat  takes 24 minutes - it's only 4.57 decimal minutes slower (19%) in the tide. It's late and I can't be bothered to work through what that means in PY terms.

Originally posted by sargesail Slow boat: Boatspeed 4 knots.  Tide 2 Knots. 1NM against the tide = 30 minutes.</span> With the tide = 12 minutes.  Race time: 42 minutes. FAst boat: Boatspeed 5 knots.  Tide 2 knots.  1Nm against the tide = 20 minutes!!! With the tide = 8.57 decimal minutes.  Race time 28.57 decimal  minutes. Sail it non-tidal - 2 NM for slow boat in 30 minutes.  The slow boat is 12 minutes (40%) slower in the tide!  2NM for the fast boat  takes 24 minutes - it's only 4.57 decimal minutes slower (19%) in the tide

Yes that's the long and the short of it, I did an article a few years ago explaining all this, blowed if I can find it now. With a few more examples it becomes clear that the speeds form an exponential curve, the faster the boat the less effect it has, conversely the closer a boat's speed is to the tide the worse it gets until the boat remains stationary uptide.

Here on the Sussex coast it's round the cans in a tidal flow of between 1 and 3 knots, we're effectively going backwards and forwards through the tide.

Our Cadets are quite numerous and sail Toppers. 3 or 4 of them are better sailors than most of the adults and yet when they race on sundays they come nowhere. We're lucky if we get 1 cadet doing the races now.

This is great for the adult ego's but disastrous for youth encouragement at club level. According to other calculations I did the Topper PY on our water should be around 1440.

Edited by transient - 22 Oct 14 at 9:42am