You’re quite correct, which is why I’ll take a conversation over an email or text or forum exchange any time. Particularly in a complicated area like this, where one incorrect use of a term or a tiny miscommunication can lead one totally off into the weeds. I would also observe it makes it much quicker to determine the bonafides of the participants in the conversation. I probably don’t need to mention the TON of opinion masquerading as fact out there. And re intent, no worries but thx for clarifying. And same goes for me if I’m coming across as less than polite.
Re para 2: I agree, and am also adamant about Smart Y’s. Respectfully, a little of the “what happens….’ you refer to here is just people not knowing what they’re doing, and doing stuff they shouldn’t be and getting into trouble. Lots of that out there.
Re 208V, I’ve never heard of just boosting a single leg. That sounds like a very dodgy solution that has all kinds of ways to go sideways. The methods I am most familiar with are just live with it - your 120V supplies are good because of the phasing between the legs, and the 240V stuff you might need? Meh, tough luck. Many appliances used in environments like this are rated 208/240 (like the Marinairrre reverse cycle heat pumps), although they are much happier at 240V. If that isn’t satisfactory, then on to plan B - a boost transformer that boosts both legs. Even better, an isolation transformer with selectable boost. Charles used to make one that automatically detected your shore voltage and boosted/no-boosted accordingly. (There are some issues to be navigated though with iso xfrmrs, but benefit exceeds problems in my opinion). I’m curious, you say “less of a problem now”, why is that?
And your final paragraph, I do not understand. To clarify: I’ll use my own boat as an example; straightforward factory Silverton, 125/250V 50A service. Prior to my major rework the last two years, it has a panel with two banks of 120V breakers fed by L1 and L2, and a bank of 240V breakers. L1 and L2 are opposite phase, but none of the 120V load know that or care. If you take that “dumb” Y that I posted a link to, you are quite correct L1 and L2 would be in phase *and limited to 30A by the shore breaker*. 240V panel would be useless of course, because with L1 & L2 in phase, it would be 0V. But the 120V panels should work just fine, no? Am I missing something, or misunderstanding you?
Cheers