there's no hm dive in firered.so that means you can't find it.but you can find it in Pokemon ruby,sapphire,emerald and more.
The short answer is no. There is no Dive, HM 08, in Pokemon FireRed.
Since dive is not a HM in firered you will have to trade a Pokemon to a friend that has ruby, sapphire or emerald then using that game use the HM Dive to teach the move Dive to that Pokemon trade it back so firered can have that Pokemon again it will still have Dive however you cannot use it to dive underwater.
Celadon City
Dive is not an HM in Pokemon firered or leafgreen however if you trade a Pokemon that knows dive from ruby or sapphire or emerald now you have a Pokemon that knows dive But you can't dive underwater in firered or leafgreen because it wasn't invented in the kanto region.
Dive is not an HM in firered if you want a Pokemon to learn dive trade it to ruby, sapphire or emerald then take it back after teaching it the move.
Dive is not available in FireRed.
The HM dive cannot be acquired in Pokemon diamond.
Their are 7 HM's available in Firered.
There's no Dive HM on Pokemon Leaf Green.
the hm dive is not available in pearl.
no
Dive is an HM, but in Diamond,Pearl, and Platnum, it is a TM