Navalizing (spelt "navalising" in the
Commonwealth) is the process of converting a piece of equipment (generally military) from its basic configuration into one suitable for use aboard ship at sea. What, exactly, the process entails will depend heavily on what the equipment is and what its use case is intended to be. This process is distinct from designing a piece of equipment solely for naval use from the beginning.
The term is used most frequently for aircraft, both fixed wing and rotary wing. The assumption here is that it is cheaper to navalize an existing, tested and proven land-based aircraft design than to start from scratch with a version intended only for use aboard ship. This makes some sense - in the former case, economies of scale can usually be exploited if the navalization process is an applique or post-manufacturing conversion, or even an 'additional step' in the manufacturing process. The more of the base manufacturing that is kept in common with the land-based (and presumably, higher-demand) version of the aircraft, the better off you are.
When navalizing aircraft, there are huge numbers of factors to consider. These depend, naturally, on the aircraft's design and its intended use. There are several general areas in common, however. The most important is that of corrosion resistance. The naval environment is a much harsher one than that faced by ground-based fighters. Salt water will, given enough time, dissolve a battleship - and the skin of an aircraft is a much, much more fragile proposition. Coatings, treatments or paints are needed to ensure that the aircraft can survive salt spray, extremes of temperature, constant high humidity and even the frequent washings that may be required.
Not just the skin is a factor. Canopies and the covers over sensors may react quite differently (and badly) to salt spray and humidity. They must be tested and modified if necessary.
Other than materiel issues, there are problems of design loads. In many cases, navalizing also includes making those changes necessary for the aircraft to operate off an aircraft carrier. If the carrier in question is a STOBAR carrier, those changes may be minimal, perhaps limited to the undercarriage, which will likely require an arresting hook or other mechanism. For CATOBAR carrier ops, however, the aircraft's undercarriage will not only need to be able to handle the load of stopping the airplane extremely rapidly, but the front gear will need to handle the load of accelerating the aircraft to flying speed, as the catapult connects there. Design changes may (probably will) be required, since normal aircraft design is an exercise in weight management and efficiency based on requirements.
The undercarriage must be strengthened in general, as well. Unlike land-based aircraft, which are designed to land lightly at a relatively shallow angle with their engines at idle, a carrier aircraft which depends on arrestors must be able to land at a very steep angle - sink rates of 8-10 meters/second! It will also land with its engines at maximum power so as to be able to safely return to the air if the recovery mechanism does not successfully engage or if the pilot misses - a 'bolter' in the parlance.
In some cases, even more structural changes are required. To live aboard ship and fit onto the elevators and into the hangar, most carrier aircraft have folding wings. Engineering a folding joint into the mainspar of an aircraft is a non-trivial task.
Not only aircraft can be navalized, of course. Computers, radars, guns, drones, radios, satellite dishes - any one of a myriad of systems that a ship may need and which had already been designed for use on shore. One famous example is the MONARC. In an attempt to engineer a shore bombardment gun for naval vessels, Germany experimented with mounting the entire turret from a land-based artillery vehicle (the PzH 2000) on board a frigate. The size of the turret was a good match for naval turrets in use at the time. However, the recoil was much higher (the PzH turret mounted a 155mm howitzer) and so damping systems needed to be added. Although that effort was successful, it turned out that modifying the systems in the turret to handle naval conditions (humidity, corrosion, etc.) was an extremely difficult - read, expensive and time-consuming - task, and the project was dropped.
Iron Noder 2010