This part of IEC 60721 classifies the groups of environmental parameters and their severities to which a product is subjected when installed aboard a ship. Ships where electrotechnical products may be permanently or temporarily installed include: " Ships propelled by mechanical means, including mobile offshore units; " Ships not propelled by mechanical means, including sailing boats and life rafts. The classes defined apply to all sizes of ship from pleasure craft to trawlers, ferry boats, icebreakers, cargo ships including tankers. The areas in which ships normally navigate are: " inland waterways (canals, rivers, lakes etc.); " coastal waters: " oceans. Areas where ships have to navigate in ice are also included. The environmental conditions specified in this document are those that the product can be exposed to whilst permanently or temporarily installed for the running, handling and safety of the ship. The environmental conditions may also be used for other products, installed in a similar way at similar locations. Accidental incidents are not included but their occurrence may need to be taken into account for products vital to the safety of the ship. The classification also does not cover the effects of water pressure on submerged products. Classification of storage and transportation environmental conditions are given in other parts of IEC 60721-3(all parts).