A sea mine is a self-contained explosive device placed in water to damage or destroy ships. Sea mines are items which are used to cause damage to hostile ships in sea battle. At the time when Voyage Century was introduced for the first time, mines were very popular among players merchants because they were a good way to cause damage to raiding ships while trying to escape from them. Since Colony Age version, sea mines were becoming less important. Output damage was too low compared to the amount of hull newer ships had. This difference is even greater now and it got to a point where mines are completely obsolete.