Rig Tenion on 311

[Mart3833]

Does any one know what the rig tenion should be on a Beneteau 311, my lower leeward shrouds have quite a lot of slack in them when sailing hard, I was given a "Loos" rig tention gage to check them and the cap shroud were reading 27 and the lowers 15.

Would be greatfull to hear from any one that knows the correct tenion settings for this boat.

Thanks
Mart