I stopped leveling up and would like to be able to continue to level up past 9 of 27 on level 51. My crew/land team continues to level up. I am playing Maelstrom Engine 2.8.3 and ERAS II update from 11/12/20.  Anyway to correct this? Still my favorite game and appreciate the time and efforts that have been spent keeping this game alive. Thank you!!

You didn't get all skills (personal and ship) on 100? If so, you can no longer level up. At least, leveling mechanic worked like that in COAS.

The character leveling is the same as COAS and I think VVV101 is correct that any skill that reaches 100, will no longer apply experience to level the character.  What you can do, is that any skill that is still less than 100, like medium fencing for example, is to equip a medium blade and then you will be able to gain experience by using a skill that is still less than 100.

Understood, thank you both for your responses. Sounds like my rank will remain at level 51. Are the new items that become available such as ships and weapons tied to level of rank? Basically are the any cool weapons, cuirass, or ships that I will not encounter because I won't make it to level 52, or 55, or higher?

I searched the ERAS items and the highest rank listed as a requirement to show for some items is Level 28, so you once you are above that, every item is available to be found.