The word "whelked" refers to having many wavy or raised lines or ridges on the surface. Synonyms for "more whelked" could include "more ridged," "more corrugated," "more grooved," "more furrowed," or "more ribbed." These words all convey a similar idea of having visible, raised lines or ridges that create a textured appearance. Depending on the context in which the word is used, other potential synonyms could include "rippled," "scarred," or "marked," all of which suggest a surface that has suffered some kind of physical damage or alteration.