> there is no fundamental reason why you can't have underwater laser weapons Even at optimal wavelenghts and clean water, seawater absorbs/scatters light so mu

> there is no fundamental reason why you can't have underwater laser weapons Even at optimal wavelenghts and clean water, seawater absorbs/scatters light so much more strongly than air that underwater laser weapons are pretty much infeasible. The best wavelength is blue-green-ish, but even there you lose 5% intensity per meter (the loss is exponential in distance).