Overloaded? Correct waterline?

[wholybee]

Is your boat overloaded such that it is not safe? Highly doubtful. Will performance suffer? Maybe. As you are just leaving, don't worry about it. As you live and sail on the boat for a few years you will adjust things. Everything in the cabin will get rearranged such that it works better for you. And you will (or won't) notice changes in performance as things change. I noticed that having 40 gallons of diesel in jerry cans on deck forward of the mast did unfavorably impact sailing. So, I only fill them if absolutely necessary, and leave port with the minimum fuel I need. I also found that I was constantly getting rid of stuff. Always trying to make room, so giving away or tossing things I though I would need but wasn't using. It's a process, that you can't really start with until you are well into your trip.

[Cheechako]

My 47 was 5"+ down on the waterline. Not good for performance I suppose, but never really was a problem either.
You still motor the same speed.
You still reach hull speed in decent wind.
Are you a light air sailor? Then it may effect you.

try to make good decisions on getting unnecessary things off the boat, but in the end... "meh".

[wingssail]

Originally Posted by MicHughV

Water line length and theoretical max hull speed, etc is all good and well on paper or in flat calm conditions, but once at sea it all becomes moot.

You'll be rockin' 'an rollin' up and down and sideways for your entire time out there, going thru' umpteen sail changes, etc, and another inch of immersion becomes meaningless.

Each day at sea, the vessel also becomes lighter, as stores are consumed, engine run time, etc, etc.

Consumable stores are a small part of the extra weight on most boats.

The extra weight affects acceleration more than final hull speed, (coming out of tacks, or recovering from wave resistance, for instance) so that is one reason why race boats try to stay light. Down on its lines does not have a lot of effect on a cruising boat's performance or seaworthiness.

That is, UNTILL the distribution of the extra weight becomes a problem. Weight in the ends such as extra heavy anchors or chain in the bow or arches and equipment over the stern can have definite and disturbing effects. First weight in the ends increases hobby horsing which can greatly slow a boat. Secondly, weight aloft reduces stability and sail carrying ability, not to mention windage which slows a boat.

These effects are not clearly noticeable, but they will be present and most likely the only thing you will observe is that the boat just is not the same as when it was light. I think it could make the passage more tiring and less enjoyable, but that is a very subjective opinion.

But you need the stuff! So focus on stowing or installing it in ways that do not detract from the boat's natural balance. Keep the weight low and out of the ends.

By The Way, of my boat's 3500lbs of stuff, I keep 2200lbs of it onboard while racing. It is calculated to cost me 6 seconds per mile. The total 3500lbs which would be present on an ocean crossing (and was), while stowed optimally, probably cost me 9 seconds per mile. On our 2800 mile crossing of the Pacific that would amount to less than 1 day's delay. But with proper stowage and close attention to detail we retained most of our boat's performance and our crossings were always enjoyable.

[MicHughV]

I never fully realized the clutter I had onboard until I sold my first boat and moved to my second boat. I had to put it all in storage for a period of time and the mountain of "stuff" was impressive.

[ItDepends]

I would encourage the OP to keep his boat as light as possible. Despite the well meaning advice here, weight most certainly DOES matter, and not just to racers.

• A hull deeper in the water has more wetted surface area, which is more drag in light winds.
  
• It is kind of true that weight matters more when accelerating than it does at steady speed, this is a total red herring to a boat. EVERY time a wave slaps your boat, it slows down, and has to accelerate again. If your boat is a slug at accelerating, you will be left far behind.
  
• If you look at the simplest rules of thumb for sizing a motor for a displacement boat the only thing they use is the weight of the boat! If weight doesn't really matter, why do you think that is??
  
• One of the biggest predictors of two similar boat's speed under sail is the SA/Disp ratio.

So, YES weight matters. None of that, however, is negating the need to carefully distribute the weight that you do have to have on board.

If you want to weight your boat, NEVER trust the readouts on the dials of a travelift or crane. Every time our boat is out of the water, I look at them, and they vary by a factor of 25% from one lift to another. Some yards will have calibrated scales that they use to weigh boats for race classifications. That's the only way to be sure.

[Bowdrie]

Although modern computer programs have removed much of the tedious calculations, one of the most important tasks a designer has to accomplish is a "Weight and Balance" study.
He does this for both horizontal and vertical planes.
The weight of each component, each stick of wood or fiberglass panel and a thousand and one other things are noted as to their location aft of the datum, (usually the stem,) and their location above or below the designed WL.
When all is finished/compiled, the results are plotted against the known center of buoyancy of the underwater shape.
This tells the designer how much weight allowance he has left for ballast, and where the fore-an-aft center of gravity of the ballast needs to be located.
Then calculations can be done which will determine the metacentric height, and this together with the other data can be used to plot the curve of stability.
Designers typically will include X amount for fuel/water, some allowance for stores, perhaps some amount for "people stuff", but it's usually pretty basic.
Over time boats always get heavier, an extra set of silverware or several anchors, it all adds up.
I would posit that most any cruising boat is floating a few inches below her designed WL.

[Idaho]

"A few inches lower" does not sound all that bad.

There must be some metric where at some point the "overloaded" boat's safety becomes compromised. To me that means its handling under sail becomes risky for broaching, pooping, rolling, driving the bow under, or other potentially fatal risks.

I do know that in following seas, such as sailing downwind to French Polynesia for a month, an exhaust pipe that is too low can present a risk of back-flooding the engine with seawater.

So back to the original question, now refined.

How far above the waterline was the Morgan 41 Out Island's exhaust hole designed to be, when the boat is in use?

That hole is the only indicator unlikely to change over time (40 years), unlike the boot stripe, bottom paint line, or scum/growth line.

[MicHughV]

Most marine diesel installations that I've seen, have some or other water lift muffler box in the exhaust line, this is to trap water in the line once the engine is shut off, but can also serve to "collect" some sea water should some come in thru' the exhaust.

I've owned several boats, where, although the exhaust exit point was above the water line at rest, it would be below the water line when heeled over and have never had a problem with this. If anything, water rushing past the exhaust exit point, may cause some some suction, removing any water in there.

Just my 2c....

[rslifkin]

Originally Posted by MicHughV

Most marine diesel installations that I've seen, have some or other water lift muffler box in the exhaust line, this is to trap water in the line once the engine is shut off, but can also serve to "collect" some sea water should some come in thru' the exhaust.

I've owned several boats, where, although the exhaust exit point was above the water line at rest, it would be below the water line when heeled over and have never had a problem with this. If anything, water rushing past the exhaust exit point, may cause some some suction, removing any water in there.

Just my 2c....

Agreed. If the system is well designed you should be able to dunk the exhaust port without flooding the engine.

[Sailmonkey]

If the exhaust is still above the water, count yourself lucky.

Our exhaust was always above water at rest, and mostly below at speed.

[pcmm]

Originally Posted by Idaho

How far above the waterline was the Morgan 41 Out Island's exhaust hole designed to be, when the boat is in use?

That hole is the only indicator unlikely to change over time (40 years), unlike the boot stripe, bottom paint line, or scum/growth line.

The Morgan OI (not Classic) has its exhaust at the bottom point of the transom. On most OI's this will be around 8 inches+- above the waterline at rest. I know when I motor this sinks to around the waterline when motoring hard. If the Exhaust system has been unaltered over the years, it will be fine, The OEM install has an exhaust loop that extends up to almost deck level so its very safe. water getting in (from outside) has to travel 12 feet horizontally (including a right angle turn at the transom) before it even gets to the elbow that turns the exhaust up to the loop.

[TrentePieds]

Idaho said: "How far above the waterline was the Morgan 41 Out Island's exhaust hole designed to be, when the boat is in use?"

That, Idaho, is a much sounder question than your first one, because at first blush it seems reasonable that if a hole in the transom of a boat lets in enuff water, the boat will fill and sink.

However, you need to consider just how the exhaust system for a boat's auxiliary engine is set up. You know already that the INTAKE for seawater to cool the engine is fitted with a seacock, and that you keep that seacock closed AT ALL TIMES EXCEPT when you are running the engine, and that is done precisely because if a hose leading from the intake to the engine should be compromised, the boat might/will fill with water and sink.

So if that is true for the intake, why would it not be true for the exhaust which is where the cooling water comes out? Why does the exhaust not have a seacock?

Well, people smarter than thee and me sorted that out in the early dawn of the use of engines in ships and boats, and second guessing them is a waste of time :-)!

So here is a handy, dandy picture of how an exhaust system is set up. Trace through it - THINK through it having some recollection of what you learned in high school physics class - and you will see that it doesn't matter how high the exhaust is located above the waterline. Or, indeed, whether the exhaust is located BELOW the waterline!

https://www.westmarine.com/on/demand...t-System-2.jpg

So in short, using the exhaust location as an indicator of the PROPER waterline is futile. There is no such thing as a "proper waterline". There IS a line around the hull located at the water's surface when the boat is afloat "fully laden". There is no way of knowing what "fully laden" means since that differs from boat to boat. That line is probably what you are looking for, since your ultimate purpose is probably to determine where to paint your "boot top". Load your boat as you would for a long cruise. Hop in the dinghy. Mark the hull with a waterproof marker at the water's surface. Come up two inches from there. That would be a good location for the bottom of your boot top.

There is absolutely no need to make things unnecessarily "scientific" :-)!

Cheers

TrentePieds

[pcmm]

Ultimately I think here you are way way way overthinking this. If you want I can run down to my OI tonight (1978 Ketch) and measure. My OI sits a bit bow down as I currently have too much chain in the bow but it can give you a rough idea of the position of the exhaust at rest. My ship is currently light as I'm not cruising and have very little in the way of extra's onboard other than my arch and panel off the stern & I don't have a generator onboard contributing to wieght.

[Bullshooter]

This may be oversimplification for the OP's original question, but can't you just measure your draft and compare that to the design draft, then subtract the difference? There are various ways to measure your draft while in the water.

[Idaho]

Originally Posted by pcmm

Ultimately I think here you are way way way overthinking this. If you want I can run down to my OI tonight (1978 Ketch) and measure. My OI sits a bit bow down as I currently have too much chain in the bow but it can give you a rough idea of the position of the exhaust at rest. My ship is currently light as I'm not cruising and have very little in the way of extra's onboard other than my arch and panel off the stern & I don't have a generator onboard contributing to wieght.

If this is not too much trouble, I would appreciate your help as you suggest. At least it gives a reasonable starting point, even if yours is a bit bow heavy. Thank you.