Flapper valve fell off

[Dr. D]

I have an Airmar triducer which is acting up. The worst issue is the flapper valve (sorry if it has a proper name) fell off. Before, when I pulled the blanking plug to inset the triducer the light coming through the opening was minimal and the flow of water in was also minimal. Now, the light is bright and there is a geyser shooting up.

Should I be worried that the thru hull is compromised?

[Davidasailor]

My flapper fell off a few years ago, and other than the geyser when putting in the blank there haven’t been any other ill effects. This was the second time it fell off. The first time it was just a year old and the dealer was showing me how to insert the blank. They replaced that thru-hull under warranty. When the next one broke a year or two later we gave up on bothering to have it replaced, as it’s clearly just a weak design.