Originally Posted by jackdale
Knotmeter. If I start to get concerned about its accuracy, I pull it and clean it. You can check the accuracy with a dutch log.
How do you stop the water when you pull the thru hull knotmeter? I have two old thru hull knot meters in my boat. Will remove all and glass in a patch on next hull out as I fear them getting knocked out and hole the boat. Which leads to next question: Why do not all these thru hull knot meters and depth sounders not require a seacock shut off? Seems these plastic "plugs" are an accident waiting to happen. Seems they could be designed to be insert into a seacock and if they were knocked out or started leaking you could pull them out and shut the seacock.