Submarine types of Nuclear Power Plants

I was thinking about how efficient a large Submarine built for the express purpose of generating power through nuclear energy could be in emergency situations? Though storms affect the surface of water through wind and waves, as a life long SCUBA diver I have noticed that if you are below about 20 to 30 feet in depth in most situations it usually isn't that bad almost no matter what is going on on the surface. So, maybe submarine nuclear platforms for electrical generation might be useful in catastrophes that happen near the ocean where emergency generation of power could be cabled onto land through waterproof cables and submarines could even go under water during harsh weather or storms and continue generating power. I know from being an electrician during my training by my Dad from 1960 until 1970 that there could be many problems with electrical transmission under these circumstances like unwanted arc welding holes into the submarine for example in an emergency situation. However, with present day technology I think all problems could be worked around with computer alerts and modern day technology to keep things on an even keel.

I was also thinking lately about Tidal Electrical Generation. There are many places on earth that have extreme high and low tides. I was thinking about an enclosed flotation lake that could be opened and closed to take advantage of the different heights of water just like a dam like Hoover Dam.