Hi,
Sims make a jacket in XXXXL, see Simms Classic Guide Jacket
http://www.fishingmegastore.com/acat...ms_Jacket.html unfortunately they don't convert that into inches so I suggest you contact them and ask them to measure it.
I've found that the 'XX' scale varies significantly from one manufacturer to another. A test in a magazine on fishing shirts XL size to be 6 inches different between the smallest and the largest.
Also don't trust the stated size, earlier this year I was after a waterproof jacket and a Tog24 46" was much bigger, I'm 50" and I could fit a winter fleece underneath it and still have plenty of room.
Cotton Traders have a wide range of clothes up to XXXXXL or 5XL as they put it. Again they tend to understate the actual size in their size lists but I've found that they are happy to actually use a tape measure to get the real size.
Look at this site,
http://www.fishingtackle.co.nz/index...eID=2145830238
see how a XXl at 46" actually measures as 65", so the Alexto Fishfighter Fishing Vest a couple of jackets lower down at XXXXL may solve your needs.
Best regards
C