An eight to ten-foot blue shark was spotted meandering the shallow waters of Dogfish Bar in Aquinnah on Saturday afternoon.

Benny Syslo, 20 of Chilmark, was out fishing for striped bass and bluefish with longtime friend Cam Alexander of Vineyard Haven in Mr. Syslo’s 21-foot Carolina Skiff on Saturday. At about 3 p.m., Mr. Syslo spotted the shark swimming close to the surface. The fish came into water as shallow as three feet, he said. They followed it for about a half hour.

Mr. Syslo immediately knew what kind of shark it was. His father is Mike Syslo, the former director of the Massachusetts State Lobster Hatchery, now a senior biologist for the state Division of Marine Fisheries.

Blue sharks are a common shark in these waters, however they are more often found farther out. Mike Syslo said that this is an earlier than normal sighting for these kind of fish, perhaps due to warmer water temperatures. He speculated that the shark may have been attracted closer to shore by the prevalence of squid.