beat the 8th gym
You go to Steven's house in Mossdeep city. He's northwest of the Pokemon Center. When you enter, he'll give you HM08. HM08 (Dive) is exclusive to Pokemon Ruby and Sapphire and is obtainable in Mossdeep City from Steven who resides there. Steven
Yes, Clamperl can be caught in Pokemon Emerald. You have to have a Pokemon that knows the move Dive, which can be taught through HM08 - Dive. HM08 is found in Steven's house in Mossdeep City, but only after you have beaten the city's gym leaders. Clamperl can be caught on routes 124 and 126 underwater (use Dive on the dark spots in the ocean).
You find HM08 Waterfall on BF4 of the Cave of Origin
Although HM08 (dive) can be learnt by some Pokemon in the Fire Red game, you can only get the HM in the Ruby, Sapphire and Emerald versions of Pokemon.
HM08(Dive) can be found at Steven's house after clearing the Space Museum in Mossdeep City. Steven's house is north of the Mossdeep Pokemon Center.
There is no HM08 in Pokemon Crystal. Pokemon Crystal has only 7 HMs that are available to use.
Steven gives HM08 Dive to you (Mossdeep City).
There is no HM08 in the original Pokemon Gold game however in HeartGold HM08 is Rock Climb which you can get from Professor Oak in his lab in Pallet Town after you've beaten his Grandson; Blue who is the Gym Leader of Viridian City.
Just Southeast of Sootopolis City, it's underwater so make sure you 1)beat Liza & Tate, 2) got HM08 Dive from Steven
There are only 7 HMs.
Go to route 128 and use dive(HM08) and you will see boat go near to the boat and press B and enter the cave you will see team Aqua members
you have to get all the gym badges in kanto