Yes, luggage, (strollers, suitcases, backpack (1 item/person)) is allowed, however a) these are only allowed on the lower level of the boat, b) you need to look after your belongings and c) you need to place them in a way to allow unrestricted passenger flow, d) your item can not block evacuation routes. Upon, the request of the staff you may need to move your belongings to a more appropriate place where it does not restrict the flow of the passengers.
Larger items, like bicycle, moped, motorbike, rented or bigger e-scooters, etc. are not allowed, please see (the article on bicycles)

