I did think shark when it was on but it could have been anything really,but it was the speed it accelerated that was what broke me off, not happy with the whiplash, great for getting the lead down in tide but to thin and easily frayed, I had a 50lb 12 ft shockleader too and it didn't break on the knots! , just the power there was quite awesome! My Rod reel and line felt completely under gunned, and was almost waiting for the line to part or run out!, mark said shall I bouy the anchor just as it broke,but even if he had and didn't brake, it would have been to late.shame tho my other Rod onboard that I think it hit first was a 30 lb ugly with a tld 20 and 50 lb viros braid that should have stood a chance! Sods law that, bottom line is if you want to get one of these unseen monsters, your going to have some sort of boat plan to do some quick thinking and actions to get the boat off the anchor and after it! Hope I'm more ready if it happens again!