Shroud tension Swan 40
I have heard varying opinions about the correct shroud tension on my Swan 40 with a two-spreader Selden mast (which was on the boat when I bought her). Upwind in about 15-20 knots the leeward shrouds have a lot of slack (several cm at the mid-point). This seems too much but an expert rigger in Denmark said it's fine. The only guidance I have found is the document for the Swan 41 in the maintenance section of the classic swan website, which sseems to indicate that slack in the leeward shrouds should be minimal. Is there a precise, scientific way to set up the rig tension for optimum performance without overtensioning ?

Dear Richard
The recommendation is that there should not be slack in the leeward shrouds at normal sailing angles.
In the Maintenance Section there is a document named Rigging Setting Up, describing the procedure for achieving the proper pre-tension. Would suggest it meets your criteria.
Kind regards
Lars