Musselbed Shoals is a dangerous spot for navigation through the channel from Narragansett Bay to Mount Hope Bay. It is even noted on colonial era maps. In 1871, a beacon was placed there followed by a new lighthouse in 1873.
This lighthouse was damaged by an ice floe when the ice moved the entire structure off the original lighthouse foundation. A new lighthouse was built with more protection. The plans for this 1877 Musselbed Shoal Lighthouse are part of the collection of the .
The stone pier was enlarged to protect the structure. The plans of the Musselbed Shoal Light show the quarters for the lighthouse keeper. The keeper led an isolated life. Most keepers held the post for only a short time. A few of them lasted as long as ten years.
Ice floes in 1919 -1920 damaged this reinforced lighthouse as well. The light was abandoned in 1938 and the lighthouse was severely damaged by the Hurricane of 1938.
Later the building was torn down and an automatic light was installed that remains today, close to the Mt. Hope Bridge.
Close to the Bristol Harbor is the Hog Island Shoal Light which marks treacherous shoals near Hog Island (which is also part of Portsmouth). There was a small light boat on the spot that the Old Colony Steamship Company used to aid their vessels. A larger boat, the Eel Grass Shoal Lightship, LV 12, was used beginning in 1886. The lighthouse was built in 1901 and can still be seen from the Prudence Island Ferry.
The "On the Water" exhibit at the Portsmouth Historical Society is opening on Sunday, Memorial Day weekend.