Saturday, 22 December 2012

More on the 4th Dimension

Some video footage from the practice yesterday.  First up, here are the tracks at the start of the session.

The wind direction was Wf2-3, the track at the bottom is a beat from Rockwood to Dunes, the track at the top is a run from Dunes to Astra.  The downwind track is full of zigzags, each of which is a transition from a broad reach to by-the-lee, or vice versa.

Here are the tracks when Andy suggested a few laps between Cambermet and Rockwood.

A few laps turned into a few dozen, neither of us was willing to give up.  Not sure that this was good practice, but it was certainly good fun (and learnt something about the tide aswell - it pays to lee bow the tide rather than tack to get out of the tide in that area).

Anyway, back to the point of the practice - learning the transitions for 4th Dimension downwind sailing.  Here is the first section of downwind with lots of transitions.

Points of interest:
- The outhaul tightens as the boom moves out, this is no good.  Not sure whether to modify the existing boom or wait for the new carbon one.
- I wonder if I'm sheeting out too far when going by-the-lee, creating too much windward heel.
- Moving from by-the-lee to broad reaching needs loads of main sheet, otherwise its a swim.  Looks like a load of practice in stronger winds.
- I wonder about the optimal rate of turn.  Steve says that the transitions should increase speed, mine feel like they slow the boat down.

And some video showing latest progress upwind.

The interesting thing with upwind sailing is that it takes full concentration at the moment, and often I'm forgetting to sheet out with the tiller hand or lapsing on windward heel.  I'm going to try even shorter straps as I'm still slumping at times.  On the positive side I appear to have located my stomach muscles, quads and hip flexors.  They nearly prevented me getting out of bed this morning, this straight leg hiking is hard work.

Andy was sailing so well in the 300 today, impressive to think that its only his second time out.  Upwind we were matched for boat speed, and he looked very comfortable in the boat.  But I thought readers would appreciate an opportunity to see Andy cooling off after all that upwind work.

1 comment:

  1. Thanks Mark. Enjoyed our little cruise. Just as well we weren't racing!