Navigation season is the part of the year when sea routes are open enough for regular vessel movement. In the Arctic and other icy regions, it is the window when ships can transport equipment, install cables, service landing points, and move crews or spare parts to remote infrastructure.
In cyber security, navigation season matters because physical access often determines whether critical communications infrastructure can be built, inspected, repaired, or attacked. Submarine cables, coastal stations, and remote network sites are easier to reach during this period, which can improve maintenance and resilience. The same access can also increase risk: an adversary may use the window for surveillance, sabotage, or supply-chain interference, while defenders use it to harden sites, verify routes, and reduce single points of failure before waters freeze again.