Translation of "Swell" in Dutch

My hand would swell up and the pain would come back.

...zwol mijn hand op en kwam de pijn terug.

Perhaps she's trying to mimic kelp or algae moving in the swell...

Misschien probeert ze kelp of algen na te bootsen.

That is protected with a big piece of kelp forest, 'cause the forest itself actually dampens the swell.

...dat beschermd wordt door een groot kelpwoud. Want het bos zelf dempt de deining.