I think the latest generation of engines with precise control of charge air pressure through 2 stage turbo charging with waste gates to precisely control charge air pressure and 2 stage charge air coolers to precisely control charge air temperature can almost completely compensate for changes in ambient air temperature. However, there are still relatively few of them in service Globally.
Modern marine Engines tend to have an HT (High Temperature) or JW (Jacket Water) enclosed Fresh Water cooling system, treated with corrosion inhibitors. This circulates through the cylinder Blocks (Entablatures), cylinder Heads and Turbocharger casings, in some cases it is also circulated through heat exchangers immediately after the Turbo charger in the charge air manifold. This will pre- heat the charge air at low engine loads (low scavenge (charge air) pressures and temperatures, in order to improve combustion. At high loads when the air temperature leaving the turbocharger compressor are much higher, the same heat exchanger acts as a first stage air cooler.
Older engines used a S.W. (Sea Water system to cool the H.T. or J.W. and the Lubricating oil and charge air.
Newer engines use an LT (Low Temperature) enclosed Fresh water cooling system, treated with corrosion inhibitor, to cool the charge air and Lubricating Oil and (usually by mixing through a Thermostatic valve) the HT coolant. This means that the heat exchangers used for this do not suffer from corrosion, Bio Fouling and blockage by mud, shells and other debris in the Sea Water.
However the LT Water still has to be cooled by Sea Water so all these problems still occur at this point.
The LT water can cooled by Tubular heat exchangers, plate heat exchangers, keel coolers, or Box coolers, but they all, except the keel coolers suffer from these problems.
Many modern ships use a single LT cooling system to cool the main propulsion engines, Electrical Generating sets,condense steam from the steam plant, Bow and Stern Thrusters, Air conditioning, and Refrigeration systems. Traditionally there would be separate SW systems for the main Engines and for the Generator sets, and probably a General Service SW pump providing cooling for the Refrigeration and Air Conditioning Plant, steam condenser, as well as Toilet Flushing water.
Hope that clears up your understanding of HT/LT!
With regard to propulsion efficiency wave action continually aerates the Sea. As I said before the dissolved and suspended Gases make Sea Water slightly elastic and compressible, and can come out of suspension and solution at low pressures, creating gas bubbles or even sheets. Cavitation is often thought of as the Sea Water boiling at low pressure, but just as with bottled beer, reducing the pressure above the aerated liquid causes it to foam. The obvious low pressure points are the at the propellers and the afterbody of the vessel, where the water that has been divided and pushed aside by the Bows is being pulled back towards the hull of the ship.
Good luck with your research, and I would like to congratulate you on your English..
It is always better to ask a stupid question than to do a stupid thing.