An oldie but a goodie.
amazed at how much water got in.
www.yachtingmonthly.com/news/how-do-you-capsize-a-40ft-yacht-4733
Easy to capsize a 12m yacht, just take it into 12m waves for a while at night
Or go beam on with a breaking wave, and the danger zone for capsizing drops to 30% of hull length.