Swim At Your Own Risk - Billy and Sheena always expect adventure when they join their uncle, Dr Deep, aboard his high tech boat. What they don't expect is a treasure hunt leading to a 200 year old sea captain who refuses to stay dead. Wave Goodbye Forever - Just when they think the tide is turning, Billy and Sheena accidentally dive into a dangerous mystery. A chilling surprise awaits them in Horrorland, the theme park where their worst nightmare is about to come to life.
