Originally Posted by djmarchand
High water alarms can help but only if there is someone to hear them or someone to do something about it.
That kind of goes without saying.
But your chances of somebody noticing your boat is sinking go way up if you at least have an alarm.
Some people hang a sign on the boat if it's unattended with contact information on it in the event the alarm goes off. You can go so far as to note on the sign if someone hears the alarm and can't reach anyone they should feel free to break into the boat to investigate the cause. A broken window is cheaper than a flooded boat.