Robert, if my boat were to sink, the cause was not easy to determine and I had installed one of the devices on my vessel would my insurance company try to use it as an excuse to not pay the claim ? I don't know.
I always think about that when I change or add something to the boat. I have never had an insurance claim so I have no idea how closely they investigate these situations. I suppose if I run my boat on to the rocks through my own negligence they would pay so maybe if I modify the boat and that causes it to sink they would also pay ?? I don't know if it would be good to ask them how this works or not ?
At this point the difference is $60, and it comes with a check valve, the hose, and piece of mind, so it is worth it to me

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fair winds, Bob