Hm 08=Dive. You can get it in Mosdeep City in Steven House.
The short answer is no. There is no Dive, HM 08, in Pokemon FireRed.
There are 8 HM's: Hm 01: Cut Hm 02: Fly Hm 03: Surf Hm 04: Strength Hm 05: Defog Hm 06: Rock Smash Hm 07: Waterfall Hm 08: Rock Climb
There are 9 HMs HM:01 Cut HM:02 Fly HM:03 Surf HM:04 Strength HM:05 Flash HM:06 Whirlpool HM:07 Waterfall HM:08 Rock Smash HM:09 Rock Climb
you have to take a journey through ice cave or something like that and get HM waterfall.after that you go there and get the sapphire. P.S. He'll steal the sapphire and you get it back at team rockets base
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.
there is no such thing is a HM called remover
You get HM 8 first from Steven in Mosdeep City (in his house). You get HM 7 in the Cave of Origin (look kind of hard - it's dark in that cave.)
You get the HM waterfall in the same cave you get Kyogre
HM 9 is Waterfall.
the hm cut is in one of the houses in rustoboro city
The short answer is no. There is no Dive, HM 08, in Pokemon FireRed.
it isn't in Pokemon platinum its in ruby and Sapphire
From your rival on Route 19.
the hm 7 is water fall you get it in sootopolis city in sapphire game
Rock Climb doesn't exist in Sapphire. It actually exist in Emerald so trade a Pokemon from Emerald to Sapphire that has rock climb!
there are many MANY Pokemon that can use the hm flash in Pokemon sapphire. the following Pokemon can: grovile( treeko),kirlia(ralts)shroomish, eletrike, Roselia, plusle, munun, magnemite, voltorb and many more
move deleter in lilycove city