ISO 12217, STIX and Dynamic Stability

[Capt Tony]

Construction progress continues and I am hopeful of getting my Cape Henry (to be named "Giggling Squid") launched this year - maybe October and I have just added a couple of dozen more photos to my Flickr building page. 

Now I have a question:

The EU "Recreational Craft Directive" lays down four operational categories - A, B, C and D where "A" boats are designed to go anywhere in the world and "D" boats only in calm inland waters. Has the Cape Henry been classified as meeting the construction and stability requirements for any of these categories. I have looked at some commentary on ISO 12217, STIX and Dynamic Stability, but don't have the knowledge or experience to work it out. I would like to think it would be a "B" category (to cope with English Channel weather...!), but there seems to be a minimum mass (DWT ??)  requirement of 1.5  mt that the CH might not meet ?

[Brian J]

I believe that she is C rated Tony.

[Dudley Dix]

The ISO rulemakers are in process of changing the way that they categorize boats. It used to be that Cat A was Ocean, Cat B was Offshore, Cat C was Inshore and Cat D was Sheltered Waters. Now they are changing it to categories based on wind strengths and significant wave heights. Some of the documents have changed and others wait in line. The wheels of bureaucracy grind extremely slowly. The new categories are:-

A. A recreational craft given design category A is considered to be designed for winds that may exceed wind force 8 (Beaufort scale) and significant wave height of 4 m and above but excluding abnormal conditions, such as storm, violent storm, hurricane, tornado and extreme sea conditions or rogue waves.

B. A recreational craft given design category B is considered to be designed for a wind force up to, and including, 8 and significant wave height up to, and including, 4 m.

C. A watercraft given design category C is considered to be designed for a wind force up to, and including, 6 and significant wave height up to, and including, 2 m.

D. A watercraft given design category D is considered to be designed for a wind force up to, and including, 4 and significant wave height up to, and including, 0,3 m, with occasional waves of 0,5 m maximum height.

The previous system was geographical, so Cat C "Inshore" limited you to close to the coast. The new system does not appear to have limits on the distance permitted from the coast, only limits on wind strength and wave height.

I guess that this is intended to give more flexibility of operation. I would expect that the CH21 is good for crossing the English Channel in moderate conditions but should not attempt crossing in a gale. Of note is that the wind strengths given are not maximum gusts, they are average strengths over a 10 minute period, so a Cat C Beaufort force 6 (fresh breeze of 21-26 knots) may have gusts well in excess of 30 knots. The maximum wind speed is not what is used to assess the category, it is the 10 minute average.

This info was given to me by the company that does CE certification on my boats and by the man in charge of introducing the new multihull regulations.

DD 

[Ron Jesche CH21' Sealion']

Tony, I guess the boat's capabilities may not be in sync. with what you're insurers may say. I wouldn't hesitate crossing the channel in 'Sealion' in the right conditions now that I have some experience sailing her. Obviously you will need to get to know your boat in different conditions and find what you are comfortable with. That big bloke from 'Jay Jay'  might be handy on board when the wind picks up! Hi Brian. I have been out in a range of conditions this year [ I try to get out at least once a week] and a couple of weeks ago went out in 25 knots to try things out now that I have some experience with her. The wind was coming off the land so the sea state was calmer than it would have been otherwise but I had a constant 25 knots for the few hours that I was out, the forecast was for 30 later in the day so did not stay out any longer. I was single handing and left the marina with full main and staysail. I did this as I wanted to practice reefing in stronger wind. Once out I hove to and put a reef in the main. These boats heave to beautifully, I often heave to when I'm out by myself to reef, or put the kettle on. Downwind was an absolute blast with speeds of up to 9 knots surfing down small waves. To windward was very manageable by myself and very little spray on board considering the day. There are a few minutes of video of this day on my YouTube channel. I feel confident that the boat could handle much more than this with another reef in the main, so it's  reassuring to know that with good preparation you will make it home safely if caught out.

Good luck with the launch in a few months ,and let us know how the electric drive works out. Just keep in mind that Sealions eat Squid for breakfast! Cheers Ron

[Brian J]

Like Ron, I have sailed JayJay reasonably hard. She sings along in force 4 and 5. She heaves to happily and I love the fact that you only have to loosen the peak halyard an inch or two to reef the main. I would always take down the staysail (I have a traditional small sized Jib) before reefing the main to avoid lee helm which can be alarming!

I have replaced the jib and staysail sheet cam cleats with quick release spinlock cleats which allow a crew not built like an ox to release the sheets under high tension.

She is OK when gusting force 6 but is not happy at the top end of force 6 (hardly surprising given she is a baby). I have got caught in top end of 6 gusting 7 and it was unpleasant - the 6 hp outboard is shallow enough thar it comes out of the water if there is any heel on the boat and, even when buried, cannot create enough forward momentum to keep the boat head to wind.
She is a wonderful boat but I now avoid taking her out if the forecast is anything more than force 5 gusting 6.

I do intend to cross the Channel in her, but will be choosing my timing carefully to get the right weather!

[Dudley Dix]

Brian, do I understand correctly that you are sailing Jay-Jay as a traditional cutter with Yankee, staysail and main? Then as the wind picks up you strike the staysail first before reefing the main? If you reef the main first while keeping the two headsails you get lee helm? If that is what you meant, I would expect lee helm to be a problem. 

Your first action as wind picks up should be to strike or roll away the Yankee, after which you will have a snug fully inboard sloop rig, which is what I intended for stronger breeze. That should give a nice helm. After that, reef then double-reef the main as the wind increases further, keeping the staysail.

DD

[Ron Jesche CH21' Sealion']

I have to agree with Dudley. When sailing Sealion as a cutter I always roll up the Yankee first and then reef the main. I furl the Yankee at about 18 knots. With a long boom weather helm is always going to be an issue, so correct sail choices are necessary. Raising the centreboard half way helps but it is usually time to shorten sail.
When I sail with the Genoa I furl this at around 15 knots, and unfurl the yankee. They don't work together.
For those with only the cutter rig, I would highly recommend saving for a Genoa. In 10 knots or less you literally sail circles around most boats on the water. The cutter rig looks fantastic,but the Genoa gives that bit extra. I have attached some pics of Sealion with the Genoa. The sunset photo was taken a few hours ago. Ron

[Dudley Dix]

Ron, I think that you have a typo in your post. You say "When I sail with the Genoa I furl this at around 15 knots,  and unfurl the yankee. They don't work together." Don't you mean "When I sail with the Genoa I furl this at around 15 knots,  and unfurl the staysail. They don't work together."

DD

[Ron Jesche CH21' Sealion']

Dudley is correct, it was a typo. Ron

[Brian J]

Thanks Dudley. 

I sail with a small jib (not genoa) in cutter sail formation. My first reefing step for me is to drop the staysail - this keeps the boat well balanced even with a full main and avoids excessive weather helm. 

If further reefing is needed, then I reef the main. This also seems to be balanced OK without lee helm. As you say, a reefed main and both headsails is to be avoided.

Works for me !!

Thanks for the advice Ron, but I am sticking with a jib rather than genoa - I am still running rings around the other boats when off the wind and she looks gorgeous with that rig !