Sci-fi related questions about submarines.

[EFileTahi-A]

Originally Posted by Synthfg

A laser underwater would be completely impractical
the light would be scattered to buggery and absorbed in a short distance,
light doesn't travel very well through water,

An energy weapon such as a photon torpedo or plasma pulse could be effective, it would have to work on the same principles as supercavitating torpedo's such as the Russian VA-111 Shkval to travel at high speed through the water without contacting it.

http://en.wikipedia.org/wiki/VA-111_Shkval
http://en.wikipedia.org/wiki/Supercavitation

Assuming ridiculous amounts of energy, magnetic shielding may be possible by projecting a strong magnetic field around the boat you could in theory deflect or detonate incoming weapons away from the hull, however the field itself would give away your location

Very interesting! Thank you very much!