This thread has a lot of good advice, I think.
I would add newspapers as a potential source. If the whole ship went down, then it would probably have made the news. The Library of Congress Reading Room has papers covering the period, so if you can make it there (or find somebody to go and look it up for you), you may find an account that you can use. (I had to depend on a newspaper story to get the sailing date for one of my ancestral ships.)
If the ship arrived safely, but Hans died en route, then I would imagine that the ship's master would have had to report that at the port of arrival. I know that was required under the U.S. government. But we're talking the colonial period, so those records may not have survived the war.
Personally, I don't see any reason not to have a "died at sea" category, but I only joined the Categorization Project this week, so it's not like I'm an authority or anything.
Ah. Poking around the categories, I couldn't find a "Died at Sea" category. (Well, there is "Category:Died_at_Sea_en_route_to_Grosse_Île,_Québec", but there's no other category like it, nor does it link to any category other than "Category:Grosse_Île,_Québec", so I'm reluctant to take it as a precedent.)
I do see that "Category:Cemeteries" does have a subcategory of "Category:Cremation", so it seems reasonable to me to add a category called, say, "Burial_At_Sea" or something like that. (Assuming, of course, that Hans was actually buried at sea. I have heard of instances where people just boxed up the corpse and took it along. I have no idea why.) I think I'd start out with just plain "Burial_At_Sea" at first, and if it ends up collecting enough profiles that people have to go to subsequent pages, then add subcategories like "Burial_In_The_Atlantic", and so on.
If you don't know whether he was buried at sea or not, then I'm thinking that somebody who's got more experience in the Categorization Project than I do would be better placed to comment on whether a "Died_At_Sea" category would be a good idea, and what category to link to from it. I couldn't find a category on "Deaths" "Deaths_During_Migration" or anything like that.
As for how to create a category, I don't think I can offer better advice on that than H Husted offered to me on my question about "Categories for immigrant ships?" so I'll just point you there.