1780 Netherlands Ducat, 'Hol' Variety Questions

The HOL and TRA just signify what province of the Netherlands the coin was minted. HOL represents Holland while TRA represents Utrecht (TRAJECTUM in Latin). Regardless, your coin is still a "trade coin" and contains 0.1109 Oz of gold.

So you recovered this from the bottom of a harbor? It looks in awesome condition if that's the case!

Thanks markn and sander,
When I started metal detecting, my friend told me that she had thrown a ring
into the water behind her house.
I started searching the area, recovering an '88 Mass Cent on the first day, if that wasn't enough to hook a newbie,
there were better things to come
the entire cove was rich in targets Colonial to present.
I dubbed it 'Cob Cove'.
I was digging for a copper signal when this piece showed up in the pile,
(I gave it a nice edge ding)
bright and shiny right out of the mud, of course first thought it was a plastic token or such till I picked up the thin yellow disc.
Carat gold becomes pitted after a time in the salt, but 23+ purity such as this coin comes out as it went in.

Within five feet of a float, people have been oh so close to this coin for a long time...
In one area is the ballast pile & beams from a early 19th C miltary transport,
stones include brain corals and other non native stones, lots of flint and volcanic glass types.
Dozens of coins and military buttons in the pile from Rev to 1830 era,
no two piece buttons, all pewters & one piece copper and brass, Scripts and Eagles,
Artilleries to Zoaves.
Been searching this cove going on two and a half years, and you still never know what's gonna come out of the old 'Iron Patch'
I've gotten early coins from 8 different countries here
Still haven't found my friends ring, though I did get a Colonial era Gold Shield ring, Believe hers is hiding under a mooring or float chain somewhere.
I haven't given up!
Again, Thanks for your replies, and HH All! Herbie.