J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment J30 Keel

Own a J30 for a year and a half now. Really like this boat. Old but good.

Crewed on a J30 and J29 when I was a teen. We won much more with the J29 in PHRF.

So its pretty obvious that Rod made the keel too small on the J30. Probably contributes to the poor light wind performance that everyone talks about.

The J29 is a similar boat. I think its a J30 with chopped down freeboard. But the keel is larger. This is a well performing boat in all conditions. I think the keel change is a big contributor.

Comparing the boats, looks they just extended the keel trunk 6” and bolted a J30 keel on.

Has anyone ever talked about or tried to lengthen the keel on a J30? Either modify the trunk or bolt on some length to the bottom?

The J30 keel is the same length as the keel on my US25 at 48”, though thicker and wider. Seems like a design miss.

This is old news, huh. No worries.

The major reasons that all of the versions of the J/29 are better in light air is the lower displacement and larger sail area, improving the sail area to displacement ratio. The J/30 isn't going to compete well with higher performance boats typical of newer designs, however, against reasonably similar boats, optimizing what you have is your best bet. Pulling off unnecessary gear and supplies, 0.5 oz spinnaker, lightweight 163% genoa, clean and smooth bottom, etc. One final item is the keel shape vs J/30 keel templates.

GL,

-Chris

My Arch Nemesis in light air is an S2 9.1 in club racing on my lake. It has a similar sail area to weight ratio as the J30. That boat weighs like 800lbs more, but very competitive below 5 kts. There are 2 of them I have to deal with! They are tough. The keel on that 9.1 is 1.3x the J30. But, in 10+ kts, I never even see them. Just walk away. And, they have an additional 1000 lbs in ballast.

In my Laser days in heavy air, I’d pull the dagger up about 1/3. It gave way better control upwind.

I am not a marine architect, but Im thinking this why the J30 is good in heavy air, not as good in light air. The keel was just a little too shallow.

Just thinking out loud. I know this boat is ancient history, and Rod learned a lot from it. Look how awesome his boats are now.

In heavy air you need to use a #3 so the boat will point and isn't overpowered. In light air I had a 1/2 Oz spinnaker that was class size and legal for PHRF (not One Design). It made a big difference for winds less than 7 kts. When I had Rhapsody, I raced against a well sailed S2 9.1 and we mixed up the results regularly with these sail combinations. The results were based on who sailed the better race because from a boat speed perspective, the two boats were pretty well matched.

I race single handed, switch to the #3 at about 13 kts true wind. People say the J30 is tender, need weight on the rail. KNOT. Raced last weekend, average 20 kts, gusts to 27. Apparent wind over 30 a few times. Had #3, full main. Almost got run over by a barge, so I was 3 minutes late to the start, was first to finish all races, and first corrected. The J30 likes the heavy stuff, even without weight on the rail.

The problem I had was on the reaches 7.5 kts boat speed. The weather helm is nuts. The rudder has a super high angle of attack. Thats gotta slow you down. It really needs another 12” in length. Anyone try to lengthen? Like use a section from a cracked rudder? PHRF of course.

Another thing I noticed is how the stern “squats” at 7.5 kts. I think its trying to plane. You could surf on the wake it was generating. I dont remember other boats I have sailed on doing that. If I had crew, I would have them sit more forward. Is that a J30 thing?

You would have benefited from reefing the main in those conditions. If single handing, consider rigging a single line reef so you can reef from the cockpit without going forward.

Fully crewed weight forward in light air is a good thing. Downwind when on a wave, you'll need to move weight aft.

The 30 sure is a pig on a reach in a breeze. Some people have fitted a balanced rudder to alleviate that problem. I don't know what it does to the feel in the tiller upwind. It's not a class legal modification, but that doesn't seem to be an issue for you.