Yup.. All mine are Bronze with shut off values and double banded as per commercial regs...
when i first got my grady the second season before I started to guide they we the original plastic ones and had 1 hull fitting pop about 2 inches above the water line... close call 
Is there anything on the market that monitors the rate of change of water level? That way the alarm will sound if the bilge goes from 0 to 1-2” (or less) of water in a short time period. Would be a lot more useful than a high water alarm that goes off a few minutes after water starts gushing in.
Correct on All accounts
This article provides a good synopsis of the ABYC requirements, along with the risks of failure in amateurish installations.
Groco is the gold standard. Good chandlers will have their products.
I believe barnacle systems will tell you how often or long the bilge pump is running. Interviewed the founder https://podcasts.apple.com/ca/podcast/business-vancouver-island/id1460284640?i=1000630365466
Cool, thanks for sharing that
That method your referring to is the new standard on any new builds on the US because of the transport regulations. It has the best side load capability and the thread pitch is correct. All this time people have been tightening FPT ball valves onto straight thread thru hull fittings. Straight thread and pipe thread are the same thread pitch, but obviously pipe thread is tapered. Basically when you tighten down a female pipe fitting onto a straight thread it compresses the male fitting. That being said that method worked for a long time and will still work if installed correctly and not tightened down too tight. Over the years alot of boats ended up with issues with thru hulls from cracking or side load movement. The flange method is all correct on all aspects of mechanical.
Call mee crazee but I have a bilge water alarm on 24/7 when our boat is moored. Three bilge pumps are on separate switches. The lowest pump keeps the bilge dry. The other 2 are for disaster so their switches are a bit higher up. This also triggers the alarm. Redundancy is cheap insurance. 2 pumps will keep up with a 1-1/4" hose failure. Each pump is wired independently, as well. At the berth, shore power is connected to keep the power up.
A high water bilge alarm is a requirement on commercial vessels - cheap version is to install a float switch wired directly to the battery with a buzzer alarm that is loud enough you could hear it while running under power.
No? Even with plastic washers in between? I know brass is a major no.. but stainless?
Nope. The absolute best way to put a thru hull in an aluminum boat is to weld in a pipe nipple that's basically long enough to be a stand pipe. So it goes up past the waterline. So aluminum pipe that's threaded on one end, welded on both side of the hull, and backing plate for side load. Even from there if you use s stainless ball valve it will corrode the threads eventually. Most guys just use marelon, they make valves also. Some guys put marelon valves on the stand pipes. Some guys put a hose over the stand pipe, using the pipe as a barb basically with hardwalled hose double clamped then into a bronze ball valve so it's decoupled. Even that system needs to come up past the water line to be legal. Things have changed in the transport regulations from 30 years ago.
If I woke up to a 97db backup alarm at the dock I might go over and scuttle the craft myself to restore the peace. Just saying
