A magrodome is a sliding glass roof found aboard passenger ships. It can be opened and closed automatically depending on the weather and is often positioned over a swimming pool to offer an indoor-outdoor setting.
The first magrodome was fitted aboard the SS Oceanic. The primary purpose of the magrodome was to shelter the Lido pool area from inclement weather. The magrodome offered a method of covering the deck in case of rain or fog, while also allowing it to be opened in sunny conditions favorable to sunbathers.
Magrodomes have since been included in a number of modern cruise ships. Some traditional liners (such as Cunard's former flagship Queen Elizabeth 2) had a magrodome placed over an existing pool.