I would think a lot would depend on what you were looking to power on board via the shore power, how that would change when 'unplugged' and how much time you were planning on spending on the boat... You will get the most power to the boat with a single 240V/50A (as opposed to a 120v/50A) inlet, but you will also pay for that in terms of wire, cables, and it might be hard to find a marina which can service you. However this service approaches what many houses had in the 70's and before, so you would be able to power almost any heating/cooling systems you wanted and not have to worry about shifting things when you plug in a hair dryer. Great for dock side, but would need a really large generator to be able to keep that much power when you were away from the dock. One other thing to consider: If you bring in a 240v ckt, be it a single 240v/50A service or two '120v/30A' feeds which you expect to bridge and get 240v, and are driving large motor equipment (e.g. Air Conditioners) which expect 240v you can have problems. Many dock provide service via a three-phase feed. For 120v this is not a problem, but if they simply take two 'legs' for their '240v' ckt you will end up with only 208v and can cause serious overheating on equipment which is expecting to get the full 240vs. It is much cheaper for the marina to install and service this way :-) There are ways to overcome this, just cost more $$$ on your boat. Other extreme is a single 120v/30A ckt. Lower cost and should be able to get this power feed anywhere. But AC and Heating from it could be a problem. Of course there are options in between. But again, I think it depends on what you are looking to power while connected, what will you want to keep powered when away from dock and how will you supply that (generator, inverter, etc..) Will you be live aboard? Spending time during hot/cold weather? -al-