I was born and bred in Georgia, and snakes are a fact of life. Size for size the most toxic of the bunch is the S.E. canebrake rattler. One autumn near where we lived a man was bitten when he climbed down out of his deer stand. He was dead in a documented 15 minutes. They were all over our yard and even came up on the porch. Never had a problem with them as they are shy and not as prone to strike as, say, copperheads and cottonmouths. The eastern diamondbacks pack a punch, being the largest venomous snake in North America. A canebrake is very big at 75 (+or -) inches. But the E. diamondback would only be "modest" at that size. The main thing about the diamondbacks is their huge, out sized heads which pack a much larger quantity of venom than any of the others.