new hobiecat sailor? Why not a mastball?

Hello everybody, if someone is tuned.
I am a novice sailor and I'm learning right now how to sail my new
hobie cat 14 but I have a little problem. Since I'm new to this I was
thinking to add something on the top of the mast to keep it on the
water in event of capsize. I weight 60 kg . Actually my hobie has the
mast which is already full of "expanded polistirol" (sorry but I don't
know the translation in english), I suppose made in Hobie, but I'm not
sure about.
What would you suggest to let me feel more careful and more safe when I
get out with the boat?
Thanks in advance to anyone which will give me any useful tip...
bye
edo