You get it after you give the gold teeth that you find in the safari zone to the Old Warren, and he will give you strength.
No its not an HM in leafgreen.
The HM's that are in leafgreen are: Cut, Fly, Surf, Strength, Flash, Rock Smash, Waterfall.
There's no Dive HM on Pokemon Leaf Green.
On route 16.
you cant
In icefall cave.
You cannot get HM Dive in Pokémon LeafGreen.Since Dive is not an HM in leafgreen the only way to get one of your Pokemon to learn Dive is to trade it to ruby, sapphire or emerald then teach it Dive using the HM then trade it back to leafgreen.
Icefall cave.
HM03 is surf
There isn't one
you get it in the captains quarters.
HM, Waterfall is in the Ice Cave on Four Island.