In the past when a party is over I’ve posted how to still access the rooms through a special link, and from there you can waddle around and explore. Rockhopper’s Quest being over is no exception, as you can still access the Swashbuckler Trading Post, Dinosaur Island, Shipwreck Island, Hall of the Viking Lords, and of course Rockhopper’s Ship. I do not think you can get the items, either it won’t work or it’ll ban you as the server will think you are attempting to hack them.
To log on to Club Penguin and access the Swashbuckler Trading Post and beyond, use the following link. Have fun! http://play.clubpenguin.com/?rm=852#login/
Special thanks to Echo006 for telling me this works for Rockhopper’s Quest. Be sure to credit him if you post it!