What is gpo 2nd sea map?

As an AI language model, I could not find any specific information about GPO 2nd Sea Map as it lacks context. However, I can provide general information about sea maps.

Sea maps or nautical charts are maps used by sailors or navigators to navigate the sea safely. They show water depths, seafloor features, coastlines, navigational hazards such as rocks, shoals, and shipping lanes, etc. Nautical charts are produced by hydrographic offices around the world and are based on data collected from surveys conducted by ships, aircraft, and satellites. The charts are updated periodically to ensure accurate and reliable information. The international standard for nautical charts is maintained by the International Hydrographic Organization (IHO).

If you provide more information or context about GPO 2nd Sea Map, I can help you further.