Center of gravity for a classic 18

[Royalblu]

I'm installing a new stronger sling lift for my 18 classic , 2003 and need to know where the CG is to get aprox weight on both slings the same.
Any help would be appreciated.
Royalblu

[Ghost]

Hmmm, do you have a trailer? If so (especially a single axle), could probably do some fun physics lab work with unloaded and loaded tongue weight/torque measures I think.

[gcarter]

A 22C is officially 64" from the transom. I'd image an 18C w/a SBC would be similar or a little less

[Royalblu]

I do have a single axel trailer.
What if i were to weigh the empty tung weight then load the boat back to the unloaded tung weight, would that mean that the CG would be over the axel?

[SKnies]

Don't forget...40 gals of fuel weighs about 250 lbs. and is well forward of the empty boats' CG.

[Royalblu]

I read on another sight that Mercury at Lake X lifts the boats with 1 sling to find the CG.
Sounds good if you have a boat yard that would do that for you.

[Ghost]

I read on another sight that Mercury at Lake X lifts the boats with 1 sling to find the CG.
Sounds good if you have a boat yard that would do that for you.

i suppose you could gently do the same test with two jacks, maybe even one.

to your earlier point, I think your notion of matching the unloaded tongue weight makes sense. Also think that with some algebra and the tongue weights, and maybe the trailer and/or boat weight, you could calculate it. Perhaps ideally with half a tank of fuel and your usual gear load. I haven't sat down to do the algebra...

[gcarter]

The truth is the CG is anything but static. My tongue weight varies by as much as
nearly 100# depending on how full the tank is, how much stuff is stuffed under
the foredeck, and where the boat ended up on the trailer.
If you have any adjustment on your post, move the boat on the trailer till it close
to correct!

[sandslot]

The CG of a boat does vary in both dimensions (vertical and longitudinally) and is very dynamic. If you are looking to place your boat on the trailer or axle position, I'd reference gcarters recommendation of 64" from the transom.....this will get you close. remember, it will vary with tank fuel, baggage & passengers. It will also vary as the angle of your trailer changes (since your tongue weight changes)

[HallJ]

George,

My Minx was the same when I measured it. Not a big surprise I guess.

Jeff