Humming sound

Those are the rudders humming, it is caused by the way the water leaves the back of the rudder. Someone that knows more will post.

Those sails are a lot older than 1980's sails, probably mid 70's? Maybe the sails don't match the hulls, who knows.

As far as the rudders humming, it's normal, lots of boats do it. Lots of guys will fair the trailing edge (back edge) using wet sand paper evenly on each side until the edge is fairly sharp, finish off with around a 600 grit to make it smooth.
It most likely will go away by doing this but maybe not. It's not really a big deal unless your going to be racing in which case you'd probably consider upgrading your rudders anyways. You can always think of interesting explanations to see how gullible your crew is, I usually say it's the whales and get away with it for about 10 seconds.
Good luck!

I am new this mutlihull thing, been sailing larger monhulls, the title says she is listed as 80. I saw a few pics of the mast for a 14 and the rigging loks alot like mine, this thing could a hoge poge, but none the less it is a whole lotta fun!!!
Can't wait to go out again next weekend!!!
I will try both the sanding and story telling

Honestly. Does the hum actually cause any loss in performance. I kinda like the hum. I have goals to hit new frequencies

If you have the lexan rudders, take a pair of scissors and drag them along the trailing edge of the rudder blade until it is even. You dont want the blades to come to a point though, so don't over do it. After that, I sanded mine down with a very fine grit. Also, with the humming you can try to adjust your rudder alignment to be sure that they are not pointing inward or outward, and instead have them pointing straight toward the bows. I also believe Hobie sells a rudder stiffening kit which consists of wafers that you can install to eliminate the vibration between the rudder and the casting. Your local dealer can help you out with that.

I have no idea at this point about preformance, but I was trying to make it wind up in sound!!!
I will check the rudders upon my return to the boat club and see if they are lexan or not. I will check <img src=

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/>the alignment as well.
I will post my findings as soon as possible.
Thanks for all your input!!!!

Skipper T;

There is a whole chapter on setting up the 16 here AND it will teach you everything you need to know about cats. WELL worth the $30 or so.

http://store.catsailor.com/tek9.asp?pg=products&specific=jqcmhpjpe

Doug

The first thing you might want to check is why the mainsail is not entirely up on the mast, there are at least 5 inches left. You want the main all the way up in order to be able to use a lot of cunningham, have a lot of mast rake and still get tension on the main sheet.

Yes it’s surely not the right main for the boat but most likely that's not what's causing the hum. Maybe it's off a 14?.. <img src=

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That's gotta be the right main - it matches the jib and the jib on a 14turbo is tiny. Remember that the whole boom floats in the mast groove - the boom looks pretty low - just not hoisted fully.

Not hoisted fully or a halyard with bad length. Of course, fixing this will not affect the humming, but it will increase performance quite a lot ..

It's definetly a 16 sail. 14's never had an 8 batten main.

Everybody neglects the leading edge of the foils... don't forget they have to be clean as well.

And... if you went from strictly a scientific view. Sound is energy, so if you go from zero sound to having sound, the energy must be coming from somewhere... so, I'm sure it's slower, but how much?? probably like the ole waxed vs un-waxed hull argument... probably not much. But it does give me a headache!!

I always think the hum is kind of cool, sort of like cards in the spokes of a bicycle. <img src=

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Here is a simple instruction from the Hobie support area about rudder hummmmm.

http://www.hobiecat.com/support

http://www.hobiecat.com/support/tech/hum.html

Thanks everyone for the replies, I have learned much.
The picture I attached was just a quick raising of the sails in my yard to make sure all worked well and according to plan before I took it to the lake for the first sail. I did not do a full raise due the wind picking up and did not want to topple the rig!! <img src=

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Who does a good job on new sails???????

Go with stock sails, the resale value of your boat will be higher, you'll be able to race within the class if you ever want to, and they are good quality.

Try one of your local authorized Hobie dealers:

ST. LOUIS SAILING CENTER
13616 NORTHWEST IND. CIRCLE
BRIDGETON, MO 63044
Phone: 1-314-298-0411
E-mail: chris@stlouissailing.com

HEDLUND MARINE
515 GREEN BAY RD.
WILMETTE, IL 60091
Phone: 1-847-251-0515
E-mail: hedlund-vsc@teamvanguard.com