Fear you'll be bored on a cruise? You couldn't be more wrong! Revealing 22 amazing activities you can do at sea, from 'walking the plank' to go-karting and relaxing on a lawn with real grass
Rock walls rise up above the decks of big Tui ships and gym staff can show you the (safety) ropes
There are ice rinks on Royal Caribbean ships, where you can rent skates, gloves and helmets
There are free trapeze and tightrope-walking classes in the sports arenas on big Royal Caribbean ships