Whirlpool stacks?

[Gitmo]

What stacks is the whirlpool skill referring to in the following skill description.

Creates a 5m Whirlpool area on the current location for 6 seconds. While in Whirlpool status, Move Speed increases by 20%, and adds 1 additional stack when Whirlpool is applied.

[Dio'nK64]

I was looking for the same answer when I noticed the buff's description when it is active under your health bar.

Whirlpool

Adds another stack if Gale is applied
Movement Speed Increases by 20%

[OneNineDeepSilence]

Whirlpool is a Longbow skill addon effect (if I remember correctly, but anyway it's from Skill Specialization effects)
That stack should be the stack that you get from the skill which had this description. I can't guess it and no longer have the game installed. Should be a frozen stack, weaken, or something.

But anyway don't just believe the description, activate and then test it, see if really gave what is promised there, and if no then just pick something else. Many of them doesn't do what is written in description, it's either bad translation or the skill changed since the description was written.