Relic sea chart cancels my treasure sense skill...
 

...or it seems to...I have a blue sea chart that boost everything and adds +1 to your treasure...my treasure skill is maxxed...I noticed I don't get many royals of a sudden when using it...so I removed the chart...and bingo...every ship I sunk jus t bout gave me royals again....toggeled em like that a few times to see...and I conclude that the sea items trump your regular skills....

I had thot the pluses would be in addition to what we already have....guess not...

That was my assumption as well. Hmm.. Kat five has the ( formerly known as lost relic) treasure sense but I have yet to sail her with it. I'll have to test your theory out.. as soon as I get all this work done!!! :( I wanna play arg!!!

...but I did find it works good in svs...lol...fast fast fast...

hmm not sure ill have to test cuz i been adding points to my treasure sense but never took the charm off and just used my own sense maybe i have better sense i hope i do!! hahahaha

It might only add "+1" if you are not maxxed on that skill, because then you have more than the max on that skill. That is why I think it does that although I think they should let you keep your 5 skill points on it.

Other modifiers change the skill panel to show "6" when active on the weapons belt.

My Treasure sense is maxed at five, with the Lucky Charm relic adding +2 treasure sense, and it is still random, I can get as many crates as I do Royals, but when I hit Royals, I tend to have 2 or 3 per ship sunk. I believe it's random. This is by testing it out over several days, averaging maybe 100 or more ships a day. And it does show a number 7 in the sailing skills tab.

...ok i will have to re-check ....its just on me chart not on me charms...