Yachts & Yachting — March 2018

PAUL WYETH

might hold true. However, it must be

emphasised that the decision will vary

according to many other factors, such as

sail area to weight ratio and so on.

In any case, getting to the front of the

fleet is not as simple as leaving any

headsail larger than the existing J3 at

home. A J3 is designed for stronger

winds and so is much too flat to provide

the power needed in light airs – a

purpose-built, non-overlapped J1 or J2

will be much deeper cut.

On the other hand, spinnaker area is

relatively inexpensive, and unlike the old

IOR days, there’s no punitive penalty on

spinnaker poles that are longer than the J

(foretriangle base) measurement. In

addition, the widespread adoption within

the IRC fleet of Code 0s (which rate as a

spinnaker, even though they are

something of a hybrid between an

oversized genoa and an asymmetric kite)

has made it feasible for many more boats

to drop cumbersome overlapping

headsails from their inventory, although

the way Code 0s are treated by the rule is

scheduled for review for the 2019 season.

BOAT WEIGHT

It’s possible to get an IRC certificate if

your boat hasn’t been weighed. However,

it’s likely that the designer’s or builder’s

quoted figures will be used as the basis

for this – and these invariably come out

on the light side, particularly on boats

built before vacuum infusion

construction became common place. In

any case, when assessing an individual

boat that hasn’t been weighed, the system

will assign a ‘light’ weight based on its

knowledge of similar boats. In the case of

a production boat, for instance, you will

be given a rating based on the lightest

boat in the series that has been weighed.

As a result, having the boat weighed –

using one of RORC’s calibrated loadcells

• will often help to shave points off the
  rating. Before doing so, check that the
  boat hasn’t already been weighed in a
  previous ownership – it will be recorded
  on the last IRC certificate, even if the
  boat has not been raced for several years.
  Is it worth re-weighing a boat that’s
  already been weighed? That’s a tougher
  question, the outcome of which will
  depend on a number of factors. You
  won’t gain a large rating benefit through
  doing so, which means it’s of limited
  value if you’re not already near the top of
  your fleet. Perhaps the exception to this
  is if the boat has had a lot of
  modifications that add significantly to its
  weight since it was last weighed.
  Remember that almost everything that’s

not bolted down must be removed for

weighing, so not all additional gear and

equipment will add to the IRC weight.

ENDORSED CERTIFICATES

While IRC was intended as a simplified

rule allowing owners to measure their

own boats and sails, it is sometimes worth

getting a RORC-approved measurer in,

particularly if you’re after silverware, as it

minimises the risk of a rival protesting

your rating. For this reason some of the

more prestigious championships require

boats to have an endorsed rating – check

the Notice of Race before you enter.

TRIAL CERTIFICATES

While anecdotal evidence can help to

give a roughideaofhowmucharating

may shift as a result of any changes made

SAIL MEASUREMENT

Mainsails and headsails shrink a little with time, so it’s

worth re-measuring every season to ensure you’re

not giving away rating unnecessarily. Similarly, check

to see that, when fully hoisted, the mainsail actually

reaches the top black band on the mast and that the

clew reaches the black band at the end of the boom. If

not, move the bands appropriately and re-measure.

Above

Inshore racing is

unlikely to take

place in sub-5

knots so deep

non-overlapping

headsails are

preferred to large

overlapping ones

OPTIMISING FOR IRC KEELBOATS

March 2018 Yachts & Yachting 35