How much weight on the tongue?

I can't seem to find any info. on this, everything I found is for a bare trailer.
Approximately how much weight should be on the tongue with both the boat and trailer?
I set up another trailer, and with the boat on it I can barely lift the tongue by hand and have to rely on using the jack.
Was just wondering if there is a guide for this.
I just moved the axle 2" forward and it helped somewhat, but still plenty heavy, of course it can't be too light either.
Before I move it anymore, I figured I better get some input on this.
On a 17' StarCraft I also have, I can put 2 fingers under each side of the coupler and lift the tongue pretty easily. Seems light, but that's the way it was when I bought it and never had a problem towing it.

I remember someone saying 2/3's of the weight should be in front of the axle. It made sense to me.

I think it's 10%.

10% of the entire trailer weight is the ideal weight.

So if the complete boat and trailer weigh, lets just say 1200 lb., that would be 120 lb. tongue weight.
That's what I'm wondering about, seems heavy and would take quite a bit of effort to manually lift the tongue.

I'd like to take back my earlier statement of 2/3rd's. 10% sounds MUCH better. Ummm...OPPS. I'll remember that!

Rule of thumb is approx 10% but if it tows ok, leave it alone.

Tim

OK: just found this on the Shorelander trailer website.
5-7% of total boat/trailer at tongue.
So a total package - boat trailer, motor, etc., that weighs 3400 lb., and using 6% as the multiplier, would have a tongue weight of 204 lbs. using their figures.
That's what I was trying to get the answer to, guess that's why they make the tongue jacks!
Thanks for the replies.

I like at least 200 lbs on the vehicle, no matter the boat weight, if possible. I've found that 200 lbs keeps the back tires firmly into the ramp, and since i launch on several steep, dirt/gravel ramps, it keeps me from spinning so I dont have to use 4x4.

I've always heard around 10% for boats and RV's.

Precision weighed on an old bathroom scale.