how many pounds trailer jack
 

So I'm trying to figure out if a 1000 pound trailer jack is sufficient for my boat. It's a ski brendella and boat weighs 2400 pounds. Do I need a jack that's rated for my boat and trailer weight?

Just the tongue weight. 1000 lbs is plenty.

Most boat manufacturers set the weight and balance of the boat and trailer a little over 500 lbs of tongue weight..

So is need about 2500 tongue weight cap?

You shouldn't have anywhere near 1000 lbs of tongue weight to the 1000 is plenty. The tongue jack only needs to support the weight at the tongue of the trailer, not the total weight.

If that jack is only loaded in pure compression on a true vertical axis, then you have plenty of capacity. However, the ability of different jacks to withstand lateral rocking is a different matter altogether. My stock jack always looked like a feeble toothpick, waiting for an excuse to snap. I was rewiring my tower one winter, and while working and moving around in the front of the boat, the boat would rock over the jack precariously to the left and right. I hated that. I, like a lot of others, have gone to a Fulton F2 jack, not just for its 1600 #s capacity, but more for its sturdiness against lateral rocking.