Hi Ross,
You need more line out there not less ...
There are a ton of big boats that cruise by and God forbid your bow gets pulled down because you have too little line.
The center of the Mudhole is about 250 ft. There are some obstructions I fish there in 210 ft. The rule is 7X depth plus freeboard. That is for the worst case seas. For me, I use 5X. Yes, I have over a 1,000 ft. of line. I have them in 250 ft. or 300 ft. lengths. I simply tie them together for the amount I need.
Do you plan to grapple hook or anchor?
If you want to grapple hook, then less line will be used as you do not want to drift off the wreck. If you anchor, I use 750 - 1,000 ft. of line with 50 ft. of chain. The chain prevents chaffing and helps set the anchor. I use 3/8" line for a 21 ft. boat. I use 5/8" for a 42 ft.
They are catching ling and sea bass on the wrecks and bluefish chumming/jigging.
It all depends of which type of anchoring, sea conditions and where in the Mudhole you will fish for the amount of line. 600 ft. is a good start. I bought mine at Lowes or Home Depot (if I remember correctly) in bulk ... I do keep them in a laundry basket. I "tie them" together with shackles.
Good luck,
Ed