Sonar is the backbone of Anti-Submarine Warfare (ASW) in SEA POWER. It comes in two types: active and passive.
Passive sonar only listens for underwater sounds, like propeller noise or machinery, and is stealthy but limited by range and environmental factors.
Active sonar, pings sound waves and detects their echoes. It’s much more effective in noisy environments but reveals your position to everyone nearby.

Keep in mind that sonar performance depends on the environment. Shallow waters, thermal layers, and ambient noise can distort or block sonar signals, so understanding these factors is critical to success.

The shadow zone is a region of poor sonar coverage that forms due to changes in water temperature and pressure. Submarines exploit the shadow zone to avoid detection, as sonar waves often bend around or are absorbed in this area.

For surface ships, detecting a submarine hiding in the shadow zone requires skillful use of sonar settings and maneuvering to change angles.

As a sub commander, moving into the shadow zone can save your life. However, it also limits your ability to detect threats, so it’s not a foolproof hiding spot. Timing and positioning are key.

in SEA POWER, surface ships are generally going to see a convergence (zones) of sonar waves at 30nm intervals.
TLDR: Draw a 30nm and also a 60nm radius (use your protractor tool dummy) around your active sonar (ship) - these are areas of highest surface detection.
If nothign is detected, you're unlikely to have enemy ships (not Sub, but ships only) at those locations. Turn that active off and keep moving Mr. flashlight in a dark room....


Surface Ship:

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Submarine:

Head explode yet?

Thermal layers, or "loyers," are temperature boundaries in the ocean that drastically affect sonar performance. Submarines can dive below the layer to block sonar waves coming from above. Conversely, ASW ships must account for the layer by adjusting their sonar settings or deploying variable depth sonars to "peek" below the layer.


Operating above the layer gives ASW ships broader detection capabilities, but subs below the layer are harder to track. If you’re a sub commander, use the thermal layer to break contact and reposition. ASW captains should coordinate with other units and use depth charges, sonar buoys, sonar torpedoes, or plain old torpedoes to flush out subs hiding below.

Know your offensive weapons, range, and their capabilities.
Practice shadowing a destroyer.
Practice going head to head with enemy submarine.
Practice anti-submarine warfare (surface ship sub hunt).
Feel free to make your own quick scenario using mission editor. it's surprisingly good!


For Ships (ASW):

• Use active sonar sparingly to avoid revealing your position.
  
• Deploy variable-depth sonar to search below the thermal layer.
  
• Coordinate with aircraft/helicopters for broader coverage:
  
  • Search Pattern: Drop sonar buoys in 8-10nm intervals (credit: u/40sonny40)
    
  • Track Pattern: Drop sonar buoys in 4-5nm intervals (credit: u/40sonny40)
• Keyboard Shortcut tip: Using a helicopter, you can queue a preset drop of 9 sonar buoys using Crtl+Right Click for a tight pattern (with weapon selected), or use Alt+Right Click for a wider square pattern. 16 can also be dropped using Crtl+Alt+Right click

For Submarines:

• Use towed sonar array.
  
• Stay silent. Minimize speed and avoid cavitating.
  
• Don't be afraid to full stop (kill) engines and listen at a stand still. (this is especially useful if sub vs. sub) and don't forget to turn occasionally to see if anyone is behind you (in your bafolds).
  
• Exploit the shadow zone and thermal layers to evade detection.
  
• Time your attacks carefully and relocate after engaging.
  
• Use passive sonar for situational awareness, but be ready to dive deeper if detected.
  
• Once you fire torpedoes, turn as they will look from the direction that it came from..