The new boat has a hot water tank with new technology to keep us from scalding ourselves in case we forget how hot hot water can get. There is a cold water in and on the left side there is a brass valve assembly that is hard plumbed into the hot water out (no hose barbs or hose clamps anywhere). This valve assembly also has a cold water in and acts as a safety mixer to keep the hot water going to the showers and galley at a non-scalding temperature. The whole boat is plumbed with PEX like tubing and plastic quick connectors.
With a "normal" setup I would drain the fresh water tank, drain the hot water tank, loosen the hose clamps on the cold water in and hot water out hoses on the tank, pull them off the hose barbs, place a short length of copper tubing between the two hoses and tighten the clamps. That bypasses the hot water tank in the winterizing process so you don't have to fill it with antifreeze. That is exactly how the winterizing process is explained in the Hunter owner's manual. With this new setup I have three hoses attached to the tank(two cold, one hot), they never addressed this new style. I don't see any other way to winterize the system other than to do what the previous owner's mechanic did, that is to fill the hot water tank with antifreeze.
I know that some people use compressed air to blow the water out of the lines, I am not a fan of that, I don't trust the process. I also have no idea how these plastic connectors work and how many times you can connect and disconnect the hard plastic hose.
I will say that the location of the hot water tank under the companionway which is lifted with gas struts is pretty damned convenient even if I don't know what to do with it.