Developing the Mark series
A modern tourist submarine has to be like the best taxi car: start reliably every morning, do its job at a minimum cost and carry passengers for thousands of kilometers without any hassle.
Mark II, also called LS 250, was the first ever tourist submarine built in Finland. The first Mark II's were delivered to Saipan and Korea in 1987. The technology was largely inherited from its predecessors – offshore DLO's (Diving Lock-out Submarines), which were designed to be lifted onto the deck of a DSV (diving support vessel) after use. Because a tourist submarine is supposed to stay in water year-round, many parts were simply not durable enough.The experience gained from the Mark II series improved our knowledge of what is required from a submarine, and led to a complete redesign of the vessel. The key focus was on better reliability, easier maintenance and improved economy, in order for the sub to better suit year-round tourist operations. Mark III is an excellent submarine with a proven track record of reliable operations. However, the battery capacity, designed for 7–10 dives of 45 minutes per day, turned out to be too small for some resorts. The battery didn't allow the air conditioning capacity to be increased, either. That's why the development of Mark IV, equipped with larger batteries, begun as early as 1992. As technology quickly developed, the new submarine generation was named Mark V. We are proud of the outcome!