Alan Rickman Ancestor

Question

So I've been trying to determine how to get one of my unconnected's off my list, and thought I'd take another run at Alan Rickman, the actor. In going back in his line as far as I could go, I came across this "John Rickman", who appears to have a slightly sourced profile with a rootsweb foundation. Digging a bit deeper, it appears that there might be a historical basis for a more famous John Rickman, a Lieutenant in the Navy, who reportedly married a similarly named wife and had children with the exact same names.

I thought this was too much of a coincidence so I've noted the discrepancies on the profile, but I was hesitant to just arbitrarily go with this without some additional evidence. Can someone look at the link below and see if the information appears to be accurate AND that it is likely that it is the John Rickman in the profile?

Thanks.

http://www.captaincooksociety.com/home/detail/john-rickman-1737-1818

Comments

And at least some additional third party sourcing with Geni:

https://www.geni.com/people/Lieutenant-John-Rickman/6000000039399988402

---

And one more - Family Search:

https://familysearch.org/tree/#view=ancestor&section=details&person=9MW9-5NY

---

I think the key is the bit about the newspaper reports saying he was 78.  If newspaper reports exist which confirm that it was this ancient mariner who married a 20-year-old girl, that nails it.