Following her salvage Holland I was cleaned, treated with an anti-corrosion chemical and put on display at the Museum. But by 1993 the boat was badly rusting all over and attempts at repainting proved futile. The anti-corrosion treatment had failed and a new solution was needed! In 1994 the Museum began building a giant glassfibre tank to enclose the submarine. The tank was filled with 800,000 litres of sodium carbonate. Soaking the submarine in this way would remove the chloride ions that were the cause of the uncontrollable corrosion. In December 1998, the soaking tank was drained down and final tests carried out. Chloride levels were now found to be extremely low - the treatment had worked!

 When Holland I was originally displayed 1983 it was "restored" to its operational appearance. The idea was to take people back in time by pretending the boat was really as good as new. After four years of chemical soaking the submarine again needed refurbishment. This time the Museum chose to present the boat as it really is. Many important pieces of equipment would have been removed before she took her final voyage to the breakers yard, but still intact are all the essential components of a submarine warship: engine, motor, propeller shaft, ballast tanks and torpedo tube. Also evident is 69 years of decay on the seabed visible in the corroded form of many components and plates.When visitors enter the new gallery they breathe moisture into the dry atmosphere, which if it were allowed to build up could stimulate more corrosion. The gallery has therefore been equipped with a powerful dehumidification system that keeps the humidity below 40% relative humidity - this low level of humidity prevents moisture from setting off the corrosion cycle.