dingy for a ten year old to SAIL

I'm planinng a dingy to teach my daughter to sail. Shell out of two sheets marine plywood etc. deck on bow and pilot seat aft sort of low, to duck the boom. Eight foot long, four foot wide.

Will have oars to row backwards like if she gets in a tight spot at the end of a lake,(or decides to go berry picking at the end of the lake).

Question is placement of mast and dagger board.

Oh yeah. this will have rigging for a jib sail, perhaps cleated to one side or tha other of a two foot wide bow, (decked).

Any input here is good. As the plan is now, mast at two and a half feet from bow and dagger board three inch toward bow from center.

Will post pics of plan next week.

 

Look up David Beede and Summer Breeze. It is also of 2 sheets but is quite elegant and the plans are free. It is also a proven design with a dozen or more having been built.

Steve

 

Multiple the wetted surface of your hull by 2 to get a rough idea for sail area in a beginners boat. 2.2 for an intermediate sailor and 2.4 for a fairly skilled sailor.

Locate the daggerboard under the CE of your sail plan, maybe cheating towards the leading edge for more cockpit room.

How did you determine the amount of rocker to utilize and have you an idea of where your CB is going to be?

 

or get plans for an 8ft class yacht at

http://www.firebug.co.nz/

 

8 foot yacht

One of the nice things about a boat this small is that you can experiment a bit, without wasting too much money if it doesn't work out quite right.

Do you have any sketches or drawings that you could post here? As I'm sure you're aware, there are many successful boats this size, as well as a much greater number that were complete flops. Here's hoping yours ends up in the first category

 

dingy for ten year old to learn to sail

1st off: you guys are awesome with the replies.

Hull plan does have dagger board 3inch fore of C which should be dead on CB.

CE will end up at CB at 40deg AA (or a bit less).

Will plan on the smallest sail on boom, 2x wet hull, but add a tall thin jib for some bow pull.

Plan has jib cleats and block pullies for any situation.

The fore side relief is my next aspect of plan.

Thank you all for your input and it will take me a few days yet to get my plan on here 'cause its not a photo, yet.

 

It's a lot easier to reduce sail when the little skipper is learning, then to add additional area once they get bored with the performance of the under canvased rig. Consider a 2.4 wetted surface sloop rig rig, but with a forward mast step to permit it's use cat rigged under main alone, while they learn. It would also serve as a heavy air reefing position.

 

You are describing an optimist.

 

Thanks...a simple and elegant solution to MY conundrum...I should have thought of it myself...especially as I have used it before. I work too darn much and sometimes I think it addles my brain!

Steve

 

Get her an "Optimist" dinghy that is complying to the rules book. Its much more fun for the kids to meet on equal terms, and the "O-boat" is a forgiving starter. Btw its fun for adults as well; here we have a "parents race around the bay" occationally....... In order to promote good racing instead of investments the winner gets a jar of beer, while number two will have two jars! Makes really tough fights on the finishing line!

 

2x of a 4x8 wet hull surface would be a sail that would run her into the far end of a lake and banned for life from access. We are not on the "sound" on the Yale racing team with a Lightning.

By my figuring, I'm getting a 7.5x 7.5 triangular sail with a7.5x 2.5 jib gives a 1.3x wet hull surface with just benough pull to get her in trouble and then let her figure it out.

I'm mounting oars and oarlocks on this thing for that occlusion

 

I'm not sure what your experience is, but 2 times the wetted surface is a fairly poor light air sailor. Lets face it, an 8' boat is a light air sailor. 1.3 times the wetted surface of a 4x8 hull is about 41 sq. ft. The sail area you've suggested is only 28 sq. ft., making for .7 times the wetted surface and a grotesquely poor sailor at best.

Again, 2 time the wetted surface is a poor sailor. The Optimist pram that has been suggested has considerably more then 2 times it's wetted surface in its sail plan.

Design the sail plan with the power to move well in light air, say 2.2 to 2.3, then if desired, start her out with a reefed sail or an otherwise reduced sail plan. When she out grows this, which she will do fairly quickly, you shake out the reef or install the full sail plan and she's got more performance potential.

 

Another way to guesstimate reasonable sail area is to use a displacement to sail area ratio. Very small boats like the Opti have design displacements that will usually amount to around 10 pounds displacement per square foot of wet area. That is a ball park figure that can be used to make cocktail napkin estimates of wetted surface area but does not apply to big boats. Use something like 0.22 times displacement for sail area. Interestingly the numerals are the same as those suggested by Par but the decimal is moved one place left. An Opti or similar boat with design displacement of 180 pounds would then use about 40 square feet of sail.

I suggest that the little skipper will learn faster and be happier with only one sail to contend with. A 40 foot sprit una rig, typical of small prams, will work better than a tiny sloop rig, especially in light air. If you are offended by square sails then consider the El-Toro (another pram similar to the Opti) bermudan rig, It has a luff of just under eleven feet and a foot of seven feet. Measured area is then about 39 feet but roaches and all tend to give them nearly 50 feet. Toros sail very well in light air but are a bit more demanding than an Opti when the wind pipes up.

 

Here's your boat!

http://www.svensons.com/boat/?p=SailBoats/Bannock

 

Under no circumstance is a "tall narrow jib" of any use whatever.