Friday, May 19, 2006

Leebowing the current

This is a responce to Tillermans request for an explanation of leebowing a current.

The senario is a reach across the tide (or current) with the wind opposing the current. The lee bow is bing pushed by the current (tide) into the wind (hence the term 'Lee bowing the current')

This is a picture of what I mean:

The current is downwards, the wind upwards, the course is across from left to right.

The point that Ant ( was making in his blog is that it makes sense to sail low on the reach some times as apposed to sailing in the big arc that most folk do as they try to keep thier wind clear.
(Boats B,C and D in the diagram)

The problem of the big arc is made worse in a current because as you approch the mark you have to sail more against the tide with the wind further aft so you end up sailing slower through the water beacuse your apparent wind is slower and against a current so that your speed over the ground is much reduced. This is especially noticable in light winds.

The trick is to sail low and crab your way across the tide keeping a consistant angle or bearing to the mark (boat A in the diagram) and thus your boat spead and your speed over the ground is consistant and much higher that those who are running down against the current to the mark. because you are inside them you almost certainly have an overlap and thus water rights at the mark.

The result can be even more noticable if the current near the wing mark is stronger than windward mark.


Tillerman said...

Thanks for the explanation. Absolutely agree. There's nothing worse than trying to run down to a mark against a current in light wind.

Ant said...

That scenario is exactly the fantastic situation.. as a "fast free" sailor going low you pretty much always end up coming into the mark at a faster rate of knots.. this is good from a position, attack and psychological effect..

Something I just thought of, may or may not work is a shall we say radical tactic... I'll post on my blog now rather than waste "comment space"..