The beach located next the village where Magnum throws the fishing net is Ka‘ula Bay, the same one used in Rapture
(6.11), and the "village" was in the trees to the north, about here
Two coves to the north
is the other cove used heavily in the episode, where the canoes were kept and the girls were swimming. It's name is Milo Cove. (Photo one
, and two
.) Paradise Cove
lu'au is the property north and east of Milo Cove, and they use the it in some of their activities.
an oblique aerial photo showing Ka‘ula Bay at the far right and Milo Cove in the middle. This brings the total number of west shore locations (that I know of) to.... two! With Milo Cove being used once, and Ka‘ula Bay twice.
"The museum" where Higgins stands in for Agatha is the Bishop Museum
link) located here
. It was founded in 1889 by Charles Reed Bishop, husband of Bernice Pauahi Bishop
. Hawaiian Hall, the building used in the show, was built in 1898. Higgins knows the area well because he attended "one of the most prestigious public schools in all of England" just a few hundred feet to the west.