Yachts & Yachting — March 2018

C/O RS SAILING; ALISTAIR MACKAY

TAC T I C A L

POSITIONING

MARK RUSHALLexplainshowtojudgeyourposition

ontheracecourseandcalculateyour

next move against the fleet

I

n last month’s feature, When to Tack?,

we referred to ‘safe positioning’: a

set of tactical principles that can be

relied on when confidence in the key

environmental factors is at a minimum.

These principles might be used when

shifts are irregular and unpredictable

in pattern, when patches of extra

wind strength are equally random

and difficult to see, or when there are

no other clear reasons for choosing

a particular part of the racecourse.

This month we’ll expand on the safe

positioning rules as they apply upwind

where we really have no confidence in

knowing what is going to happen next.

In these conditions, consistent results

usually build from a conservative

accumulation process. Your overriding

goals in these conditions should be to:

Make the most of every small gain

Consolidate at every opportunity

Put the boat in the position most

likely to create the next opportunity

Which is the long tack?

If the beat is based on fixed position

rather than laid marks; if it is skewed

by cross tide; or if the mean wind has

changed since the course was laid,

the upwind leg may be significantly

skewed. This means that one tack

will take you closer toward the

windward mark than the other.

In fig 1 (overleaf), if there is no change

in wind conditions, both Yellow and

Blue will take the same time to get to

the windward mark, though Blue will

have a much easier layline call. If the

wind shifts right once Yellow reaches

IN ASSOCIATION WITH MANUFACTURERS OF PERFORMANCE HARDWARE

the layline, Blue will be close to laying

the mark and Yellow will overstand,

causing him to sail extra distance.

If the wind shifts left, Blue is

able to tack and cross ahead

of Yellow. Any change in wind

direction results in a gain to Blue.

Look for the gains early

The most conservative call is to keep

with the majority of the fleet, start better,

and sail faster! But if we need to make

a strategic gain, we do have to separate

from the other boats at some stage.

If we are going to be bold, the

time to do this with the least risk is

at the bottom of the upwind leg; for

example, tacking early while there is

the biggest time for an expected right

shift to arrive gives the best possible

chance of the plan succeeding. If

there is a bit of a left shift at first, no

worries: there is plenty of time before

you are forced to tack at the layline.

Splitting from the fleet mid-beat

means there is less than half as much

time for the expected effect: the edges

of the course approach very quickly and

we’ve seen from above the danger of

being the first to arrive at the layline.

Bank the advantage

In oscillating conditions, a shift to the left

gives an instantaneous advantage

to the boats on the left, and the bigger

the sideways separation along the

gain line (a line perpendicular to the

wind direction), the bigger is the gain

Left

Picking the

right moment

to tack is often

the difference

between winning

and losing,

whether it be in

an RS200 (facing

page) or Merlin

Rocket (below)

Consistent results usually build from

a conservative accumulation process

March 2018 Yachts & Yachting 73