The WIT SERVICE IV is a 123 foot long tug which sank in 1979 while towing a barge.  The Tug Boat sank port-side-down after hitting Dry Rocks and is resting on a sandy bottom at a depth of approximately 80-100 feet.  The wreck is now mostly covered in beautiful coral and sponges and home to the occassional Hawksbill turtle.  Look for the large grouper that hangs around the stern.