Estimates of the abundance of the American lobster, Homarus americanus, in the inshore fishing grounds of Maine were made at monthly intervals by diver biologists from August 1965 through August 1967. Pairs of divers searched 540 m2of ocean bottom at the 6-12-m and 18-24-m depth intervals at two stations in the Boothbay Region of Maine. Comparative estimates of lobster abundance were made at adjacent depths of 30-60 m from the research submersibles PC-8 and Deep Diver. The relatively constant estimates of lobster abundance shoaler than 24 m suggest that large scale seasonal movements into and out of the shallow onshore fishing grounds does not occur.