Stainless steels for cutlery have a tendency to spot after use in salt water. All stainless steel knives need a rinse in fresh water after use. Dry after use and apply a thin layer of silicone grease or paraffin to prevent the formation of surface oxides. Any oxidation stain can be easily removed with a common ink eraser.
Abrasive treatments are strongly not recommended: would damage the special surface treatment.

Sharpening
The knife comes sharpened and must be maintained as such in order to function properly and safely.
The serrated edge can be revived only by a special tool.