Originally Posted by chriscritchett
Would love to know how Tad estimated the GM for his numerical exercise? Seems a little loosey-goosey to be declared 'safe' so authoritatively. Unless he knows something we don't.
First, yes, I know something you don't.
Rather I have some experience that's relevant. It's an educated guess at the worst case.
I estimated GM based on my experience and my general knowledge of the particular boat in question, and then used a conservative fudge to create a "worst case".
The typical smallish fiberglass production boat, relatively lightly built, fairly wide, not particularly tall, with relatively shallow draft, with full fuel and two people aboard, will have a GM somewhere between 2' and 3.5'.
The Sundowner tug is low, has no flying bridge with hardtop and AC, no huge deck crane and RIB on the rooftop. In normal full load condition GM will be 3.5' or more. But adding 12 people on the deck and trunk cabin will raise G quite a bit. So I reduced GM to 2.2', though I believe it will be higher than that. Pretty sure if everybody stood on the PH roof GM could be 2.2'.