Menu
Allianz and Afloat - Supporting Irish Boating

Ireland's sailing, boating & maritime magazine

In association with ISA Logo Irish Sailing

UK Sailmakers on How to Optimise a J/109 for IRC Rating

27th October 2020
Racing the J109 Whiskey Jack in Hong Kong Racing the J109 Whiskey Jack in Hong Kong Photo: Guy Nowell

Racing a J/109 in IRC has its compromises because you're sailing with asymmetrics, you're limited to certain angles and only so much boat speed is generated both up-wind and down. While living in Hong Kong, I raced the J/109 Whiskey Jack in class 2. This is an extremely completive class dominated by three A35s and other boats such as Sunfast 3600s, an X-35 and a 34.7. We had to sail our arses off to do as well as we did.

The owner of Whiskey Jack wanted to see how he could improve his J/109 to be more competitive. Realising he probably would have to leave some of the boat's one-design components in the rear-view mirror, he contacted UK Sailmakers Ireland having seen what we had done with J/109 ratings in Ireland. To get an overall evaluation of the entire boat (including sails, rig, set-up, etc.) I got onto Kevin Dibley who I have worked with a lot at Dibley Marine. Over more than a few cups of tea, we checked out all aspects of the boat to see where we could improve upwind and down.

J109 Whiskey Jack Racing in the St James Place China Coast Regatta 2020. Photo: Guy NowellJ109 Whiskey Jack Racing in the St James Place China Coast Regatta 2020. Photo: Guy Nowell

We set for ourselves three objectives: 1) increase her upwind boat speed, 2) improving her pointing ability and  3) to reduce her IRC rating. Not a small assignment!

We started by considering how to improve her upwind VMG. We set out to reduce the wetted surface area of the boat while maintaining the waterline as much as we could. To achieve this, we looked at reducing the internal weight in the boat; but we also looked at the external weight and what could be done there.

To get the internal weight out, we replaced as much of the loose furniture as we could with lightweight carbon foam boards from ZLXC. The carbon boards were cut down to match the floorboards and painted in white non-skid. Next, we went to work on the exterior of the boat. We started by replacing the original aluminium mast with one made of carbon manufactured by Axxon. Swapping out for a lighter mast saves us a lot of weight and, importantly, the reduction in tipping weight would keep the boat upright. The set-up of this mast would be exactly the same as a standard J/109 mast apart from one small aspect…the material from which it was made and the masthead crane.

J109 Whiskey Jack - the original aluminium mast with one made of carbon manufactured by Axxon Photo: Guy NowellJ109 Whiskey Jack - the original aluminium mast with one made of carbon manufactured by Axxon Photo: Guy Nowell

Having reduced the hull and mast weight by a significant 200 kg, we set out to optimise her upwind performance. We started by focusing on a power-to-weight ratio so that the boat would perform at her optimum rating at 8-12 kts, the typical wind speeds in HK. Reducing the 140 % overlapping genoa to nonoverlapping headsails gave a big reduction in her rating, but we then had to make sure she could still perform. The worst thing we could have done was to create a scenario where we left the boat terribly underpowered. But using the "twist" designed headsail that we developed in 2019, we found we were able to achieve the optimum pointing angle and balance upwind. That met one of our objectives. We then added UK Sailmakers carabiners on the headsail luff to make the hoist and drops faster to get the asymmetric to set quicker and stay up longer.

Carabiners were added to the headsail luff to make the hoist and drops faster and to get the asymmetric to set quicker and stay up longerCarabiners were added to the headsail luff to make the hoist and drops faster and to get the asymmetric to set quicker and stay up longer

We had made major strides at this point, but we weren't done yet. We worked further on the balance of the boat while focusing on getting the maximum drive out of the mainsail roach. We ended up increasing the crane width on the mast so we could align the girths on the mainsail. The mainsail maintained its luff curve but increased the J/109 girths, and the head of the mainsail became a lot wider (0.4 m), made possible by the larger masthead crane of the new mast. This was key to reducing drag and increasing the power at the top of the rig. We were able to do this while maintaining the balance of the boat and its increasing pointing ability by adjusting the rake of the mast.

A deeper running asymmetric with an area of 111m², slightly larger than the J109 Class standard was used for Hong Kong’s light airsA deeper running asymmetric, slightly larger than the J109 Class standard was used for Hong Kong’s light airs

Given the lighter airs in HK, we designed a deeper running asymmetric with an area of 111m², slightly larger than the J109 Class standard. The new kite, combined with the reduced wetted surface area and a new fat head main, allowed Whiskey Jack to sail deeper and more square than the other asymmetric boats. She was able to creep away downwind at a lower and faster angle than her opposition. With the reduction in rating from 1.028 down to 1.019, the boat now enjoyed a massive reduction in rating while increasing her boat speed upwind and down. Whiskey Jack went on to clean up at this year's China Coast Regatta in HK.

The boat now is superbly balanced and sails higher and faster than she ever did and she does not heel as muchThe boat now is superbly balanced and sails higher and faster than she ever did and she does not heel as much

The owner went on to say after his victory: "The most significant differences in my view were the change to the carbon mast, the new Titanium sails from UK Sailmakers and a well-tuned rig with an appropriate mast rake. The boat now is superbly balanced and sails higher and faster than she ever did and she does not heel as much – i.e., I can sail the boat flatter than before – that gives the extra height and speed in my view.

Once again, UK Sailmakers put together a team of experts to make a boat faster, easier to sail, and a better experience for the owner. What more could anyone ask for?

uksails topper

About the Loft

UK Sailmakers Ireland brings modern professional sailmaking to Irish Sailing.​ Formerly known as McWilliam Sailmakers; the company was started 47 years ago to bring the latest technology to Irish sailors - we continue this mission today.

Under new leadership in 2018; our loft is dedicated to fulfilling the needs of all Irish sailors. ​As sailmakers, we do not just design sails for boats. We design and build sails for your boat. Our extensive and versatile product line allows us to produce sails to suit your requirements and expectations.   

​As a core loft within the UK Sailmakers Group, we are uniquely placed to draw from a worldwide pool of knowledge and experience - these ties have been recently strengthened with the return of Barry Hayes and Claire Morgan from Hong Kong. ​Barry held a key role in our primary production facility on Hong Kong Island for the past fifteen years. With their return comes a renewed focus on technology R&D on Irish waters.  

​With a wide variety of sailing conditions and an impressive pool of talent, the Irish cruiser racing fleet is the ideal testbed for new technologies.​ 

​As with all things in sailing; the secrets will be closely guarded - but for the first time in decades Irish sailors will be at the forefront of sail technology development.​

Although much has changed; some constants remain. The same great sail and customer service we have provided in the past will continue, as does our commitment and passion for growing the sport of sailing all over the country. 

Barry Hayes [email protected]

Contact Information:

UK Sailmakers Ireland

Hoddersfield Mill

Crosshaven

County Cork

P43 EY26

Republic of Ireland

Tel: +353 21 4831505

Fax: +353 21 4831700

Email: [email protected]

Barry Hayes

About The Author

Barry Hayes

Email The Author

Barry Hayes, Director of UK Sails Ireland, managed the main UK Production facility for UK Sails in Hong Kong until last October and has been a sail designer with UK sails for over 15 years.

We've got a favour to ask

More people are reading Afloat.ie than ever thanks to the power of the internet but we're in stormy seas because advertising revenues across the media are falling fast. Unlike many news sites, we haven’t put up a paywall because we want to keep our marine journalism open.

Afloat.ie is Ireland's only full–time marine journalism team and it takes time, money and hard work to produce our content.

So you can see why we need to ask for your help.

If everyone chipped in, we can enhance our coverage and our future would be more secure. You can help us through a small donation. Thank you.

Direct Donation to Afloat button

Featured Sailing School

INSS sidebutton

Featured Clubs

dbsc mainbutton
Howth Yacht Club
Kinsale Yacht Club
National Yacht Club
Royal Cork Yacht Club
Royal Irish Yacht club
Royal Saint George Yacht Club

Featured Brokers

leinster sidebutton

Featured Webcams

Featured Car Brands

subaru sidebutton

Featured Associations

ISA sidebutton dob
ICRA
isora sidebutton

Featured Events 2021

vdlr21 sidebutton

Featured Sailmakers

northsails sidebutton
uksails sidebutton

quantum sidebutton

Featured Chandleries

CHMarine Afloat logo
osm sidebutton
https://afloat.ie/resources/marine-industry-news/viking-marine

Featured Marinas

dlmarina sidebutton

Featured Blogs

W M Nixon - Sailing on Saturday
podcast sidebutton
mansfield sidebutton
BSB sidebutton
sellingboat sidebutton

Please show your support for Afloat by donating