help identifing prop zinc nut

[magna 6882]

I got my crab pot caught last summer and while i got my pot back fine i was missing some line. I was playing with the go pro and discovered some line and a problem with the prop zinc. The diver ask me if i new the size and type so he could get it picked up before coming to the boat.Any ideas on what i had?

 

[magna 6882]

got a better picture on my existing situation.

 

[jimdavi]

Call Trevor, he will know the size.