Balancing a boat after stowing heavy stuff

[jsc7]

With some boats in the sleep-4 category, I have thought I might remove the twin bunks and convert the "guest room" into a utility room for spare parts, fishing gear, computers, tool chest, etc.

One possible issue with this idea is that if the kitchen is on the same side of the boat, now I am adding tool chests, computers and other heavy stuff to the same side with the refrigerator, stove etc. It could lead to an imbalance in the boat.

I read an article on the importance of balance, but the article did not go into details on how to detect an imbalance or correct it.

(1) How can I tell exactly how well balanced the boat is? (or what the degree of imbalance is)

(2) If I need to balance a boat, do I just put lead counterweights opposite the CG? For example, in the aforementioned "utility room" example, the corresponding location opposite the CG would be somewhere in engine compartment. So, bolt some lead weights down in engine compartment?

[Cheechako]

Just view the boat in the water from astern and from the side. You could add Zinc or Lead ballast to balance it, but you are just adding more weight to carry around, so your initial inclination was good, try to move things around.

[jsc7]

Originally Posted by Cheechako

Just view the boat in the water from astern and from the side. You could add Zinc or Lead ballast to balance it, but you are just adding more weight to carry around, so your initial inclination was good, try to move things around.

Unless there is a witness line or something to compare to the water level, it might be difficult to detect some imbalance conditions just by eyeballing it.

[Cheechako]

Originally Posted by jsc7

Unless there is a witness line or something to compare to the water level, it might be difficult to detect some imbalance conditions just by eyeballing it.

That's true to some extent. Cant say I've seen many boats without a waterline or bottom paint line except very small ones though!

[UNCIVILIZED]

What you want in order to be able to measure the angles which your boat does or doesn't have is called a Lev O Gage (AKA Inclinometer). They greatly resemble levels used in building structures, & carpentry. But are calibrated to measure angles of tilt (heel, or trim). And you can install them so that they measure heel transversely, trim fore & aft, or both.

Some have scales graduated finely enough so that you can measure changes as small as a fraction of a degree, while others are just good down to within a few degrees of measurement.

In order to alter the trim of your boat, yes, you'll need to move weight around. And if you don't care to add more weight (ballast) to the boat, you can alter her trim by shifting the positions of some of the heavier objects. Such as batteries, tankage, dense stores like canned goods, tools, etc.

The reason for tuning a boat's trim is to optimize her performance. Think about how your car handles with just you in it. On both dry, grippy pavement, & on slippery roads. And compare that handling to when you have a 300lb passenger in the other front seat, under similar conditions. How about this as compared to a 150lb passenger in the same seat? As well as to when you have a large passenger up front, & a trio of 200lb guys in the back?
Very, very different handling if you get even remotely close to the car's limits, intentionally or not, right? Braking, accelerating, & cornering are all altered. Including understeer & oversteer.

And if such terms are unfamiliar, oversteer would be how your car handles when you have 2 dozen, 90lb bags of powdered concrete in the trunk. You don't want, or need to use nearly as much steering wheel input as you do if it's just you in the car. Otherwise if you take a corner at speed, the car's ass end will soon be passing the front, as you find yourself involuntarily leaving the road on the outside of the corner.

Whereas most cars are purposefully setup with a fair degree of understeer. So that the faster you go through a corner, the less responsive the steering input. That way you have to over correct a bit. And this is so that when a novice/non-performance driver enters a corner a bit too fast, they don't accidentally use too much steering input, & wind up leaving the road backwards, due to centrifical acceleration causing the car's ass end to spin harder than the driver had planned for/anticipated.
It's a designed in safety feature in most vehicles.

Well, boats are much the same. An excercise that I do with sailing students, racers especially. Is to tie off the rudder on centerline, & then have them steer the boat via sail trim & crew weight placement. Some balk at it at first, but with a bit of coaching, see that it's possible. Even on 70' boats that weigh 30tons... in winds of 5kts or less even.
And most of this is accomplished simply by moving a few 200lb guys around by 8-10' on such a boat. So you can imagine how much trimming a boat differently can & will impact something smaller.

And much like a race car, you generally want to trim a boat so that as little rudder input as necessary is required. Since every time you turn the rudder, the boat slows down a tiny bit.
Think about how much drag force gets created by a canoe paddle when you're using it as a rudder to steer, when the canoe is moving at higher speeds. Rudders work much the same way in boats.

Also like a car, boats perform best with heavy weights being, low, centralized, & balanced.

[GrowleyMonster]

Better to stow heavy, dense stuff on the light side, well outboard, rather than add ballast. If you never need all your available fuel range, you could carry an empty tank on the heavy side. Maybe add a water tank on the light side.

You can make a very accurate level out of a length of clear vinyl hose long enough to reach rail to rail and a few feet more. Fill the hose with water. Drop the hose so that the water level at one end is level with some fixed point such as the handrail or caprail or whatever. Check the other side and see if it agrees. Gravity sucks down on the water on one side of your boat exactly the same as on the other side. You can also make a clinometer out of the same hose, curved and attached to plywood in an arc with one bubble in it, center true vertical marked, and graduated along the arc in degrees. Fill the hose with water but leave one small bubble, then seal the ends. The bubble will read the heel or list angle. Or just buy one. https://www.westmarine.com/buy/rieke...zhAaAn5f8P8HAQ is a crude but inexpensive one.

[JD-Odyssey]

After having a genset installed some years ago, I noticed our boat listing to port (with water tanks and fuel tank filled and holding tank empty). I made the assumption that my mast was perpendicular to the deck of the boat and strapped a level to it (on a calm day) to confirm I wasn't imagining things. I really didn't have anything below decks to move around to compensate. So, I bought a couple 25# bags of lead shot and had the bags reinforced with heavy canvas. (I didn't want the shot to break through the cloth bags or the lead leaving an oxidation trail.) It only took about four or five well positioned bags to counter the listing. When cruising around the bay, depleting water from the water tanks, carrying varying volumes of fuel and gradually filling the holding tank I'm sure has an effect on sailing a port or starboard tack. For me, adding the weight just made me feel better not seeing any listing with the boat sitting in the slip.

[Stu Jackson]

The very best lead ballast is a battery!!! Actually quite useful, too.

[JD-Odyssey]

Originally Posted by Stu Jackson

The very best lead ballast is a battery!!! Actually quite useful, too.

lol, agree there... problem I had is my 4-6 volt batteries were already positioned as far starboard as they could go. The shot bags could be squeezed into places where another battery or two wouldn't fit.

[toddster8]

Re: Inclinometers. There's an app for that. I use it all the time. Depending on the use, the only tricky part is deciding what is "zero." The one for iPhone that's just called "inclinometer" even has a voice calling out the measurements, so you can hear the effect while you're moving stuff around the boat.

My 10K lb boat has a distinct port list, which drives me crazy. Because the galley, sail locker chart table, electrical panel, and all associated fixed equipment are all on the port side. I guess the empty seats on the starboard side are supposed to balance when they're full of meat. But usually it's just me.

It drives me nuts when I have a piece of gear to install and the only place it really fits is... on the port side! But according to the inclinometer, if I lay down on the starboard settee, the list disappears. As long as the water tank isn't empty. I'm seriously considering moving the batteries over there, especially if I expand the bank. But just adding otherwise useless ballast doesn't really appeal to me. The discrepancy is small enough that just paying attention while stowing cruising provisions should probably even things out.

[Dave22q]

If you laying on the berth brings your boat to balance, I think your 'problem' is in your head. Two hundred pounds more or less should not impact your sailing in any discernible way. Do you normally adjust your sheets if a guest moves from port to starboard? How many millimeters?

[toddster8]

Well, maybe 400 lbs (counting the water in the tank), but it does make a noticeable difference at the waterline, in the slip. And any water on the sole always finds its way to the corner by the galley.
Also the boat definitely sails faster on port tack, but that may or may not be a causal relationship.

[Pete7]

Originally Posted by Dave22q

If you laying on the berth brings your boat to balance, I think your 'problem' is in your head. Two hundred pounds more or less should not impact your sailing in any discernible way. Do you normally adjust your sheets if a guest moves from port to starboard? How many millimeters?

Thats's about 100 kgs or a 100L of water. I can tell if our 130L water tank is nearly empty by the lean on the mast.

To the OP if you are looking at smaller yachts with your post about 4 berths then there are many things that will change in use including water, fuel, people and food etc. Having a couple of heavy tool boxes or a genny that can be moved from side to side or bow to stern will help.

Pete

[Captain-Avenger]

The last thing I would do is add dead weight, such as lead. Move things around to balance the boat. What would your reply be if somebody told you take bags of cement and stack them up on one side of your boat? I know what my reply would be, and I won't put it in print.

[Dave22q]

Originally Posted by Pete7

Thats's about 100 kgs or a 100L of water. I can tell if our 130L water tank is nearly empty by the lean on the mast.

To the OP if you are looking at smaller yachts with your post about 4 berths then there are many things that will change in use including water, fuel, people and food etc. Having a couple of heavy tool boxes or a genny that can be moved from side to side or bow to stern will help.

Pete

I think you miss the point. I do not question if you can detect a lean but question if it makes a practical difference. After sheet adjustment do you really believe she will be faster on one tack than the other?