Visitors to Oahu, Kauai and the Big Island can join in a free whale-watching experience on March 29 when they will not only be on the lookout for whales but also be counting them.
Humpback whales come to Hawaii each winter to mate and calve, and the Hawaiian Islands Humpback Whale National Marine Sanctuary tracks their numbers during the Sanctuary Ocean Count that's held one Saturday morning each January, February and March.
The count's website provides details of the various locations.
"The purpose is twofold," said project manager Jordan Ching. "We don't claim the data we collect is scientifically accurate…but it provides a snapshot of broader trends. Even more important is the awareness that's spread."
Recent whale counts have been encouraging, Ching said.
"What has been generally accepted is their North Pacific population has been slowly increasing," he said.
Participants must register no later than March 26.
Each location has a limited number of slots. The counts begin at 8 a.m. and continue until 12:15 p.m.