Welcome back, Elin! Are you counting down the days until your Disney Cruise Line
adventure? If you haven't already, be sure to download the
Disney Cruise Line Navigator App. Once onboard, you'll be able to use it to access the activity schedules, ship maps, menus, and a texting feature to keep in touch with other guests you know onboard. There is also a countdown on the app, so you can see each day how long it is (in days, hours, and even minutes!) until the day you set sail! I love it!
I believe you're asking about the Fish Extender Exchanges. This is something that is not sponsored by Disney Cruise Line, but is set up amongst guests themselves when they meet prior to the cruise in online Disney fan forums. I suggest checking on Disboards.com under the Disney Cruise Line Meets section, and also doing a search for your ship and sail date on Facebook. You'll hopefully find a group that has started of other guests on your exact sailing who are chatting and getting to know each other before the cruise. Many times, the groups will set up a small gift exchange with each other to add some extra magic to the trip. Outside each stateroom is a clip in the shape of a fish or starfish or seahorse. Guests will hang pockets from this clip, thus "extending the fish": a Fish Extender. This is where other guests will leave little treats for those in their exchange group.
Don't wait long to check in on these groups because most of the time, they'll set a deadline to close the exchange, giving them all enough time to create the gifts for those signed up. I hope you're able to find your group online and join in if you'd like, Elin. My family and I have participated many times, and the kids really like distributing the gifts, and of course finding surprises each time we return to our stateroom.
Have fun planning, Elin!
Marcy