Marinisation (also marinization) is design, redesign, or testing of products for use in a marine environment. Most commonly, it refers to use and long-term survival in harsh, highly corrosive salt water conditions. Marinisation is done by many manufacturing industries worldwide including many military organisations, especially navies.

In some instances, cost is not a guiding force, and items may be designed from scratch with entirely non-corrosive components engineered and assembled to resist the effects of vibration and constantly changing attitude. In others, particularly in "marinising" an existing product that was not designed specifically for a marine environment for sale in the public marketplace, a balance must be found between the competing criteria.

There are three main factors that need to be considered for a product to be truly marinised.

Marinised metals include some of the following:

Marinised electronics use one or more of the following protection methods. In most cases more than one method is used:

Marinised batteries are usually gel batteries or sealed maintenance-free batteries. Not using marinised batteries in salt water can be deadly in an enclosed environment for many reasons: