That can be found in icefall cave. also
Seaking learn waterfall naturally at level 40
waterfall
its located on four island in the cave
In Icefall Cave, in Four Island
In icefall cave at four island.
In Icefall Cave, in Four Island
you get it in icefall cave on 4 island clear the ice to get to the ladder that will lead you to the HM waterfall.
on Island #4 in icefall cave icefall cave
you first have to get hm waterfall then you go in icefall cave up the waterfall then go in the ladder and there.
There Are Only 7 HM's In Pokemon Firered. Hm01- Cut Hm02- Fly Hm03- Surf Hm04- Strength Hm05- Flash Hm06- Rock Smash Hm07- Waterfall
In the Seafoam Islands, east of Cinnabar Island. You need HM Waterfall, though.
You can get HM Waterfall in Ice Cave (Four Island). You'll need Surf and Strength to get to it. Push various boulders around and fall through a few holes and soon you will find the HM on a ledge.
The short answer is no. There is no Dive, HM 08, in Pokemon FireRed.