I would certainly agree with 10 years in salt water although very few
people actually do. I can't remember seeing or hearing of a dismasted
coastal cruiser.

I know of a couple, and one of them belonged to me. The exact cause
was never determined but the rigging was in fact older than 10 years,
close to 20 in fact.

I would suggest inspection by a professional rigger every couple of
years. Dismastings are no fun and it will definitely take a chunk of
time out of your sailing season. Insurance companies also have a bad
habit of trying to find reasons for not covering the loss.