Here is the official explanation of what the Activity is, which can be found on the same page where builders should share their submissions:
Exploring the oceans will always be an awesome adventure! But how would you travel across them? We’re asking you to show us your awesome ships, with the wind in your creative sails, show us your pirate ships, cruise ships, speedboats or maybe even a jetski!
This is part of a series on LEGO Ideas that gives little tasks for builders to get involved with – there are no prizes, they are just a way to get involved with building something quick for fun. Each challenge is intended to be something quick and fun, unlike the more in-depth building required for a competition or product idea.
The deadline for this Activity is June 16 at 10.00am CEST.