Design and Construction
The boat has a raked stem, reverse transom, stub fin keel with centreboard, and internally mounted spade rudder. Ball’s centreboard is lead-ballasted with a hydraulic lift and tackle where the cylinder moves about one quarter of the travel anchor. The last hull, Silent Partner II, was instead completed with a fixed keel anchor. At 51.75 feet overall, 33,800 pounds displacement, and 13,800 pounds lead ballast, its capsize screening of 1.68 marks it as offshore-capable.
Rig and Handling
It carries a Bermuda masthead sloop rig; a 51 XL version had a taller mast and larger sail area anchor. The inboard diesel drives direct to a single prop, and the centreboard gives about 5.9 feet board up and 9.9 feet down for flexible draft.
Accommodations
No interior plan is detailed beyond owner three-cabin and ex-charter layouts seen used; one completed hull took a fixed keel.
Known Issues
No structural or mechanical defects appear in the sources; the only notable event is the 1994 factory fire halting production.
Refits and Ownership
The class is tiny — at least five built plus the post-fire sixth — and the XL rig and fixed-keel example show semi-custom treatment.
The Verdict
A low-volume Ball-designed cruiser with variable-draft hydraulics and scarce numbers.
Pros
- Lead-ballasted centreboard with hydraulic lift
- Variable draft 5.9 to 9.9 feet
- XL rig option with taller mast
Cons
- Very few built; three lost to 1994 fire
- Only one fixed-keel example
