The Melcombe Regis Boys' School on Westham Road was a Victorian board school that had served its working purpose and was sitting empty when the 1971 exhibition arrived. The building had good light, generous rooms, and enough wall space for the collection that the Friends of Weymouth Museum had been quietly assembling for years. In 1972 a permanent museum opened in five galleries arranged chronologically, with a sixth space for temporary shows. It told the story of Weymouth and Melcombe Regis from prehistory through to the 20th century - the Roman finds, the medieval port records, the Tudor union, George III bathing in the bay, the boat trains and the seaside boom. For sixteen years it worked. Then in 1987 the building was earmarked for demolition to make way for Weymouth Marina, and the museum had to find somewhere else to go.

Devenish Brewery had ceased brewing in 1985, leaving behind a handsome Victorian industrial complex on Hope Square just south of the inner harbour. Weymouth and Portland Borough Council and the brewery's owners turned the buildings into Brewers Quay, an indoor shopping arcade with cafes, gift shops, and space - the museum hoped - for displays. A twenty-five-year agreement was signed between the museum's Friends and the developers, and the collection moved in. Brewers Quay opened in June 1990. Weymouth Museum opened beside an attraction called Timewalk, which took visitors on a walk-through journey of the town's maritime history from the 14th century onwards. The arrangement was supposed to be permanent. It was not.

In 1999 the museum split from Timewalk to become a separate charitable trust, reopening in 2000. The Brewers Quay owners changed their plans; the museum lost its space. The complex reopened as an antiques emporium in 2013, with temporary room for the museum, which reopened in December that year. Then in 2016 it closed again. The emporium itself closed in 2017. In January 2016 the Council had approved an ambitious plan from the Weymouth Museum Trust to expand within Brewers Quay as part of a wider redevelopment, with 300,000 pounds in costs - some from the Heritage Lottery Fund, with 94,000 pounds pledged by the council. The trust got close. In March 2018 a small selection of the collection went back on display in temporary exhibitions inside Brewers Quay. The 2020 grand opening did not happen. Plans stalled, money ran short, and the building's redevelopment did not move.

Refusing to disappear, the Weymouth Museum Trust took a different approach. On 30 May 2022 a pop-up shop opened in a vacant unit on St Thomas Street - half museum, half gift shop, displaying a rotating selection from the collection that the public had not been able to see in years. It stayed open until 27 October 2023. A second pop-up opened in a nearby unit in summer 2025. These were not failures of ambition; they were demonstrations that the museum was not closed, only homeless. Volunteers ran the displays. Local history continued to be collected, catalogued, and shown. The full collection sat in storage, waiting for the redevelopment of Brewers Quay to resume.

Construction on Brewers Quay restarted in 2024 under new owners, with completion expected in 2026. Space has been reserved for the museum on the ground floor of the redeveloped complex. If the schedule holds, Weymouth Museum will have a permanent home again roughly fifty-five years after that first temporary exhibition celebrated the joining of the towns. The collection it returns with will be larger and more varied than what moved in back in 1990. Pop-up displays gather artefacts as readily as conventional museums do, and the lean years did not stop people donating. The story Weymouth Museum tells - of two rival towns becoming one, of a small port becoming a Georgian resort, of fishing boats becoming ferries becoming yachts - has gained a few more chapters since 1971. Some of them are about the museum itself.