Smaller vs Larger

[DJBrookster]

Originally Posted by oldman66

We will take all the precautions we can with what resources we have.

So I take it you have fully operational nav lights and the batteries are in good order.

[oldman66]

I am not up there yet. The survey is today. Having said that, the need for a new bank of batties is on my buy list as a precaution. I am pleased someone else thoght it was a good ideal. Thanks

[Adelie]

Originally Posted by MarkSF

Surely it's the SA/D (sail area to displacement) ratio that governs behaviour in various wind strengths, and that tends to be fairly constant for the same class (cruiser, racer) of boat, regardless of length.

For a 20ft and a 40ft boat, both with SA/D about 20, you'll be reefing at the same wind strength.

Alas not so.

Stability goes as the 4th power of the length (assuming all dimensions scale equally), while overturning moment scales to the 2nd power for the same wind speed. A longer and therefore wider boat can carry more sail longer than a narrower shorter boat. In practice navel architects increase beam more slowly than length because then boat speed can increase more, L/B has significant effects on speed for the same length and weigh hull. Also letting the beam scale with the length has advers effects on comfort and capsize resistance. The final effect is usually something akin to the righting moment increaing as the 2.5th or 3rd power of the length, still doing better than the overturning moment.

On the other had movable ballast has a bigger effect on smaller boats because the crew weight is a bigger percentage of total boat weight.

Shape of the hull and ballasting also affect stability and therefore also when reefing becomes advisable.

[oldman66]

Which further confirms that a larger boat is more stable in a 40 knot wind that a smaller. The wind force on the sails is the same. What is diffenct is the "effect" that translates to the boat. The same winds on a straw is more overpowering than the winds on a tree. Very good technical stuff.Thanks

[Ex-Calif]

Originally Posted by oldman66

Since I have very little real experience I refer everything to Wikipidi are someone with on this Foruma. Thanks you made look it up to get myself straight on the sheet. My Dad was 1294 and he told me this.HA

Seems like - a) we are separated by a common language - You should start calling things what they are called today. I don't know many 717 year olds - LOL... and b) You are a novice sailor looking to move a boat that is about to be purchased. Forgive me if I overstep my assumptions.

For part b) I am sure you are reading. I like Keep It Simple Sailing and The Sailing Handbook for beginners. Read everything you can, including this forum and soon you will begin to decide what is good advice and what is not...

Originally Posted by oldman66

Good info. So much to do. The boat has been setting for about a year. The cost of cleaning will give me a peace of mind. Thanks

It's good you are getting a survey. Most folks around here will provide you 12,000 punch list items before you can move this boat. At the end of the day you will have to use your judgement. It sounds like you are aplanning a coastal cruise with night stops which is nothing more than a bunch of day sails one after the other. If so the likelihood of getting caught in a hurricane are pretty remote - LOL...

Unless I am misreading you are not planning to make this a straight through passage with 2 people - i.e. 4 on 4 off watches for 15 days straight. If so I would reevaluate your plan.

Originally Posted by oldman66

I am not up there yet. The survey is today. Having said that, the need for a new bank of batties is on my buy list as a precaution. I am pleased someone else thoght it was a good ideal. Thanks

Good you are getting a survey.

In regards to the "very experienced" small boat teacher. I am guessing because it hasn't come up that he is not a "certified" teacher and that he is a young man you know who is really active in the dinghy small boat fleet and has taught others to sail. If I mis-guess please forgive me but the reason I am guessign this way is that if he is a professional teacher he would have likely moved up to big keep boat teaching a long time ago.

A 41 foot boat has lot's of momentum. Maneuvering in and out of harbor will be the biggest challenge. Underway I am suspecting you will motorsail a lot. So in therms of boat handling if you both take it slow and careful and keep an eye out for how much sail you've got out for conditions you will be fine.

Most guys I talk to about coastal deliveries pick a target speed based on the boat, in your case say 5 knots. If the boat speed falls below 5 knots the iron genny comes on to assist getting to target speed.

Sailing on a timetable has temptations to "press on" regardless. Make sure you stay safe, motor sail to stay on the plan and don't worry about being a "purist' and sailing all the way - the focus is the delivery.

Now - you and your experienced guy should be able to handle that, however I think you have one risk here and that is "who is in charge?"

It sounds like you have little experience and he has lots of experience in the wrong size boat. If something does come up it should be clear who makes the decisions. if I were going to join you (not to be rude but) I would insist on being skipper even though it's your boat.

In your case he's got the sailing knowledge and no experience on big boats. You own the boat. You oughta decide up front what's going on.

BTW - Pending a good survey and a clean bill of health on the engine, this is really a low risk delivery - go have fun!

[hellosailor]

66-
" the need for a new bank of batties is on my buy list as a precaution." Battery replacement should be an objective decision, based on measuring the performance of the electrical system, and not just a precaution.
On a "new to me but I'm going to own it and we're going to sea now" boat, I would want to put hands and eyes over every inch--every last inch--of the electrical system. Make sure every connection and cable it clean and tight and properly done. Make sure with a hydrometer that every cell in every battery was good, or not. that's the objective part of replacing them--or not. (I'd use a multimeter first, but that's a personal decision and hydrometers may burn your clothing up but they don't need calibration or fuses.)
At the same time you need to check alternator, regulator, primary fuses, spares for the fuses and belts and belt condition/tension. Or be carefree and just fill the icebox and cast off. As Napolean said, I'd rather have a lucky general than a good one?

I've seen some confusion about wind and sea state in this thread. I've been out in 28' of sturdy boat in "Force 8" when the sea state was Force5 and it was just the wind at Force 8. The wind was no problem, the sea state (8-10' mainly) would have been nasty but all crew knew the boat and knew how to keep it under control. Doesn't mean it wasn't a wild ride, exhilarating but not scary and no real loss of control at all, just certain things that couldn't be done.

A bigger boat might have been WORSE, as the sails become too much for one or two people to handle. The sea is relatively smoother (comparing wave heights to overall boat length) but you're riding a much bigger horse, and if it was light displacement, it probably would be riding rougher as well.

I'd also expect that a "small" mistake in a 40'er stands a much better chance of tearing a sail, than in a 28'er. Although at some point the question arises that you really should be carrying and using storm sails in that weather.

All things to consider--and make objective measurements and decisions on, not just precautions.

[Nico Domino]

Having made the transition both ways, it is the same logic. If in doubt, reduce sail, if you think of it, reduce sail, if you are considering it, reduce sail. A couple of days on board before the voyage are essential to understand the boat. Have a safe voyage!!

[Stefan373]

You might want to consider shipping the boat