Hi Andrew, thanks for your reply.

With regard to anchors: seabottom was about 15 m. deep and consist of fine sand. No way a small anchor will hold my cat in 30 kts. in that condition.

And righting bags (waterbags?) were not on board. At this moment I'm pondering if they are workable in my conditions.

Now after one night sleep, I more and more realize that what happend yesterday at sea had definitly to do with faults and mind-state of me.
In fact I was not cold-blooded enough; the situation took over.
So, I have to kick my cat again on its side and practise uprighting. In fact what I was used to do in the past for fun and beach audience.

Plus I indeed have to re-evaluate the uprighting system which I use and its backup.

So, that doesn't make the shock less, but I take it all as a warning. Imagine this happening in wintertime (when I sail also)!!!