Cruising the Great Lakes? Then moor with Jefferson Beach Marina. JBM offers full service, transient dockage capable of accommodating vessels up to 125 feet. Located on the St. Clair Shores Nautical Mile, come to experience a thriving marine community offering local shopping, dining, nightlife, special events, and attractions. On land, Marina guests enjoy the convenience of wireless internet, cable TV, shower facilities, laundry room, community decks and many other amenities you expect from a full-service Marina.