Today, that dream has become one of central Maine’s newest waterfront seafood destinations at 341 Water St.For Claire Crocker, 27, and Tracy Crocker, 56, opening the seafood truck was never part of a long-term business plan. Along with inspections and creating the menu, they also completely renovated the food truck before opening day. Their signature lobster roll is what Rolls on the River is all about, featuring generous portions of fresh Maine lobster. Claire Crocker prepares a fresh Maine lobster roll beside her mother, Tracy Crocker, Friday in their food truck, Rolls on the River, at 341 Water St. in Randolph. The seafood truck is open from 11 a.m. to 7 p.m. Fridays, 11 a.m. to 6 p.m. Saturdays, and from 11 a.m. to 5 p.m. Sundays.