About 20 North Atlantic right whales were spotted south and southeast of the Vineyard on Tuesday, the National Oceanic and Atmospheric Administration confirmed. This is the second report of right whales seen near the Vineyard in a month.

On Feb. 15 six right whales were seen from the air halfway between the Vineyard and Nantucket. On the same day two more whales were seen swimming south of Nantucket.

The sightings on Tuesday were off South Beach in Edgartown and have been recorded on a website NOAA maintains to track the endangered migratory marine mammals, which swim north at around this time of year. As a result, NOAA has now extended the voluntary vessel speed restriction zone in waters around the Vineyard and Nantucket until March 13. Mariners are asked to re-route or reduce their speed to 10 knots or less.