Navy SEALs’ original missions centered on hydrographic reconnaissance and underwater demolition, crucial for potential amphibious landings. While the importance of hydrographic reconnaissance is sometimes questioned in today’s high-tech world, it remains a vital capability that the U.S. military wants in its arsenal, especially in potential large peer-to-peer conflicts. The need for these skills was established during World War II with the creation of the Navy’s Underwater Demolition Teams (UDTs), the predecessors of the SEALs.
  

Key Points: 

1. Hydrographic reconnaissance involves mapping out coastlines, while underwater demolition focuses on removing obstacles for amphibious landings. These missions originated with the Navy’s Underwater Demolition Teams during World War II.
2. Extensive planning is necessary for both recon and demolition missions, involving the identification of target beaches, insertion methods, and optimal pathways for invading forces.
3. The missions can be highly dangerous, with SEALs potentially having to place explosives under enemy fire in scenarios similar to World War II-style amphibious invasions.
4. Modern technologies, such as drones and unmanned platforms, have led some to question the relevance of these traditional SEAL missions.
5. Despite technological advancements, the U.S. military still values the capabilities offered by hydrographic reconnaissance and underwater demolitions, considering them important for potential future conflicts.

Source: https://www.sandboxx.us/news/the-navy-seal-teams-two-original-and-little-known-missions/