Knobbed Whelk

The Knobbed Whelk (Busycon carica) is one the largest shells found on Delmarva beaches. The shells range in color from white, violet, and brown. They are predators and eat all types of clams and bivalves (mollusks). The knobbed whelk will wrap its “foot” around a bivalve, pry it open with the edge of its shell, and insert its mouth parts to feast.
Knobbed whelks typically grow up to nine inches in length, but can reach twelve inches. Their range is most of the Atlantic coast from Cape Cod, Massachusetts to northern Florida. Unlike the channeled whelk, the whorl of the knobbed whelk has knobs protruding along the whorl or spiral. The shell is covered in fine striations or lines.

Knobbed whelk shells are also used for making wampum by Native Americans.
Whelk is also edible. However recreational harvesting in Delaware is not allowed, except by commercial pots. You cannot just pick one up and take it home. Many collect the shells. In Delaware it is not allowed to take shells off the beaches, but everyone does anyway.
Return of the whelks, we took a couple hundred shells to the beach one day and returned them to the sea. We find more knobbed than smooth whelks after storms washed up on beaches. Probably due to the fact the channeled whelk shells are more fragile and thinner than knobbed whelks.

Commercial Regulations for Whelks in Delaware
State of Delaware TITLE 7 Conservation Shellfish
CHAPTER 28. Conchs (Whelks) Busycon Canaliculatum and B. Carica