Personally I think he should have tried to see her before meeting George the second time, even if they had limited time. A very simple "Hey, i'm sorry for all the shit I've caused for you and me" from both of them with an agreement to try work it out later would have been a start. No reason he couldn't have gone to the graves after.
Well yeah, we don't know how much time had passed after the first meeting and the second, i think George said something like 2-3 weeks in their first meeting...
But i think it is safe to assume that both were more occupied with the death of their parents, each in their own way.
Jaye had additional to her grieving likely also to deal with formalities that time, friends of the parents etc. she sure didn't have a easy time in these weeks.
MC was likely consumed by quite the guilty conscience, that he left, was away for 5 years and lacked the courage to go back sooner and will never have to opportunity to make up with them.
I don't really think u could 15 years of pain (for both of them) make up with a short talk and saying sorry, even a month on the yacht may too short for that.
Personaly i would have found it nice if Jaye/MC would have gone to the grave together before the meeting with George, i think that would have been a good opportunity to start over, even if they don't talk about the past at all, just as a symbol they still have and care for each other.
Where i question the MC is, why didn't he tried to call Tara after he couldn't reach Jaye 20 times, i mean that would have made sense and from Taras reaction i'm pretty sure she and MC stayed in contact at least from time to time.