It's my buddies tube. We have an HO Havoc and it's seems plenty big for 2 adults or 3 kids.
I was actually going to post this in the Merc forum or other forum to find out. Is there a capacity listed on that tow point? I don't see a warning label. I should check my manual.
The X-20 pulled us out with no issues and stayed planted real well. I do run cobra fins and I do think they helped keeping the stern planted. As big as that tube was, it did tow nice. I do see that the 20' Challengers do throw a considerable amount of spray. I may go to a longer tow-rope.