Hey Peter,
Good to see you have a Seacraft fan Finster on you side.
Sounds like you have the engines/electrical stuff under control and remided me that there is a section in my owners manual for sumerged motor care.
Here is an article and i am sure others have links
web page
As for structual not an expert but should be fine after a good dryout. No sure the best way, but think some tarp cover, open all hatches and get some air flowing.
Hope others can help, there has to be some other good articles on this unfortunate event
.... Nick