In his poem, The Midnight Ride of Paul Revere, Henry Wadsworth Longfellow described HMS Somersett on the night of April 18, 1775:

Just as the moon rose over the bay,
Where swinging wide at her moorings lay
The Somerset, British man-of-war;
A phantom ship, with each mast and spar
Across the moon like a prison bar,
And a huge black hulk, that was magnified
By its own reflection in the tide.

Now HMS Somerset has risen again like a phantom, this time from a beach on Cape Cod, near where she sank on Nov. 2, 1778.

British warship Somerset resurfaces off Cape Cod

The wreck of the British warship HMS Somerset III, which was guarding Boston Harbor the night Paul Revere slipped by on his legendary journey to Lexington in 1775, has resurfaced in the shifting sands off Cape Cod.

Federal park officials, saying they may have only a limited window of opportunity, are seizing the moment and having the wreck “digitally preserved’’ using three-dimensional imaging technology.

“We know the wreck is going to disappear again under the sand, and it may not resurface again in our lifetimes,’’ said William P. Burke, the historian at the Cape Cod National Seashore, noting that the last time any part of the Somerset had been sighted was 37 years ago.

The Somerset fought in the American Revolution and had a crew of more than 400. In 1775, Paul Revere slipped past the ship before beginning his ride to Lexington to warn the colonials that the British were on the move. In his poem “Paul Revere’s Ride,’’ Henry Wadsworth Longfellow called it “a phantom ship, with each mast and spar/Across the moon like a prison bar.’’ The ship sank on Nov. 2, 1778, off the Cape.

After erosion from recent storms, about a dozen of the Somerset’s timbers were found poking through the wet sand at low tide in the national seashore in Provincetown. Park officials hired Harry R. Feldman Inc., a land surveying company from Boston, to make the three- dimensional rendering.