I also like checking out who the institution's contacts are (go to their Profile, then scroll down). (The Brooklyn Museum's behind the scenes sets are fascinating.) If you check out the Library of Congress' Flickr site, be prepared to search by tags, because they have over 4000 images in only two sets, so browsing by set may take a while--a fun while, but a while.
The true maritime treasure on Flickr? Here you go:
- Australian National Maritime Museum
- Independence Seaport
- National Maritime Museum (U.K.)
- Northwest Seaport
- Wisconsin Maritime Museum
Use the "people" search to find more!