Interested in Language
The tanker market is relatively buoyant, and those yards with a significant tanker repair business, like Lisnave in Portugal, and several in the Middle East, have found that it is loyal tanker owner customers that are keeping their repair operations largely afloat right now.
In my opinion, the bolded fragment is a cleft sentence, which puts emphasis on the customers.
Does the bolded fragment mean that "loyal tanker owner customers are, to a large extent, keeping their repair operations out of debt right now".
"Largely" is directly related to "afloat". What do the native speakers think?
On second review, yes, actually, you are correct. Your words do say that the repair operators are being largely kept out of debt.
I instinctively went for a different inference because I consider that one is either in debt, or not. This isn't really a grey area. From that [possibly erroneous] assumption, I took your meaning to be that many things are responsible for the repair facilities being kept afloat, but tanker owners are the ones mostly responsible for that fact.
There is nothing to apologise for. I think I am right. If I were 100 % sure, I wouldn't visit this forum.