One, the yacht doesn't roll over. It is balanced by the keel, which is under the yacht. It is a counterweight 2-3 meters long and weighs 5-7 tons.
Second - we always sail along the coast. We stay overnight in a closed bay or marina.
Third - in bad weather forecast we do not go to sea.
Fourth - the yacht has rescue equipment, life jackets, boats, rocket launchers, radios. If even theoretically something happened, you will not have time to swim, as the helicopter will arrive.
And the fifth - if you do not get carsick in a car, you will feel great on a yacht if you follow safety rules.