Well Arjan it's very simple.

The dolphinstriker is the backbone of your cat and it takes all the compression load of the mast (and sails!).

So, regular maintenance on this item is very important. The aluminium bars (de strippen) should be snug (strak) at all times. Measured with the mast off!!!!!!!!!!!!!.

Grab a bar just in the middle between the side and the rod (rod=het verticale stangetje vanaf de bal naar beneden) and feel the tension. It should have no more play then a few mil. (Max.5 mm)

Before giving the bars more tension you should loosen the ball on top of the mast step (maststep=de aluminium plaat plus verhoging die op de beam is gepopt waar de rod met schroefdraad doorheen loopt). It's also called a mastpost.

So you can screw the rod unlimited down incase the ball was completly down to the post.

Because you are spi-ing also, a good tensioned and well maintained dolphin striker is a life saver!