Sorry to barge into your question to Mohammad.
But just as some addition information for you. I have installed a Galvanic Isolator as well last year because of the poor electrical system here in the marina.
I’ve installed a Mastervolt GI7 that is basically a double GI 3.5 in a single enclosure. This is an isolator based on HF-switching technology making it far less heavy then a conventional one. It works well although I do think Mastervolt missed big time on an opportunity to make it much more clever. Actually the device is not made by Mastervolt but by a Dutch OEM that also produces the Mass line of devices sold by Mastervolt.
For one they could have made it fairly easy into a frequency conversion device as well (50<=>60 Hz). Also the regulation of the output voltage is not possible (out voltage is in voltage plus a few %). Finally they also offer a version of the Isolator that can convert 110 to 220 that is not available (?), at least not when I was shopping.
I had some conversation with tech support at the time but their Customer Relation skills are well below par.
So all in all the thing does what it’s supposed to do but Product Management has been sleeping with this thing. For me the main point aside from isolation is the weight as the thing lives in the rear lazarette (see picture). As the 54 is already very much tail-heavy I don’t want to put too much additional weight that I can avoid on the back.