Remember it takes ships miles to stop and it would be unlikely they would be able to in some cases even if you were seen.
Straight line stopping distance is a red herring to some extent - large vessels can undertake a "Williamson Turn" (Google it) so could get back to the ditching point in reasonable time if you are spotted.
However, it is far from certain you will be spotted unless the vessel has been alerted of an imminent aircraft ditching by the coastguard - reduced manning levels means that the OOW is typically the sole lookout during daylight hours
