Certain standards and classifications are set by the ISO (International Organization of Standardization) when using equipment in a marine environment, and that includes hoist and crane equipment. The two major factors to consider are the effects of the marine environment on the equipment, as well as the effects of the equipment on marine environment. Both should be preserved with a greater emphasis on preserving the environment in which we are working.
List of Marine Environments
| Marine Zone | Description of Environment | Characteristic Corrosion Behavior of Steel |
|---|---|---|
| Atmosphere (Above Splash) | Minute particles of sea salt are carried by the wind. Corrosivity varies with height above water, wind velocity and direction, dew cycle, rainfall, temperature, solar radiation, dust, season, and pollution. Even bird droppings are a factor. | Sheltered surfaces may deteriorate more rapidly than those boldly exposed. Top surfaces may be washed free of salt by rain. Coral dust combined with salt seems to be particularly corrosive to steel equipment. Corrosion usually decreases rapidly as on goes inland. |
| Splash | Wet, well-aerated surface, no fouling. | Most aggressive zone for many metals, e.g., steel. Protective coatings are more difficult to maintain than in other zones. |
| Tidal | Marine fouling is apt to be present at the high-water mark. Oil coating from polluted harbor water may be present. Usually, ample oxygen is available. | Steel at the tidal zone may act cathodically (well aerated) and receive some protection from corrosion just below the tidal zone, in the case of a continuous steel pipe. |
| Shallow Water (Near-surface and near shore) | Seawater usually is saturated with oxygen. Pollution, sediment, fouling, velocity, etc., all may play an active role. | Corrosion may be more rapid than in the marine atmosphere. A calcareous scale forms at cathodic areas. Protective coatings and/or cathodic protection may be used for corrosion control. In most waters, a layer of a hard shell and other biofouling restricts the available oxygen at the surface and thus reduces corrosion. |
| Continental-shelf depths | No plant fouling, very much less animal (shell) fouling with distance from shore. Some decrease in oxygen, especially in the Pacific, and lower temperature. | N/A |
| Deep Ocean | Oxygen varies, tending to be much lower than at the surface in the Pacific but not too different in the Atlantic. Temperature near 0 degrees Celsius. Velocity low; pH lower than at the surface. | Steel corrosion is often less. Anode consumption is greater to polarize the same area of steel as at the surface. Less tendency for protective mineral scale. |
| Mud | Bacteria are often present, e.g. sulfate reducing type. Bottom sediments vary in origin, characteristics, and behavior. | Mud is usually corrosive, occasionally inert. Mud-to-bottom water corrosion cells seem possible. Partly embedded panels tend to be rapidly attacked in mud. Sulfides are a factor. Less current than in seawater is consumed to obtain cathodic polarization for the buried part of the structure. |