ice path
In the jonto
Once you find the Team Rockets lair and you beat them and you catch/defeat the Voltages Lance will give you whirlpool.
You get it by teaming up with Lance and defeat the Team Rocket Headquarters. Lance will give you Whirlpool once you defeat them.
whirl islands
Whirlpool isn't in Pokemon Yellow Version.
Whirlpool and if you don't like lots of randome pokemon battles a a few max repels would not hurt
it is in icecave near mahogany town
You'll need the HM Whirlpool and teach it to one of your Pokemon and you can pass the Whirlpools blocking Whirlpool Cave.
You cannot get the TM/HM Whirlpool in Pokemon Black or White.
First, travel to Olivine City. Then, surf Southwest of Olivine to get to a Whirlpool. Then, use a Pokemon with Whirlpool to go across the whirlpool to get into the Whirl Islands.
you have to get hm whirlpool
You get the HM Whirlpool from Lance after you infiltrate Team Rocket's Secret Base in Mahogony Town.