More questions about float plugs

[guy48065]

I read the recent discussion about plugs & plug types so last weekend I had a closer look at mine. Each log has 3 ports with what appears to be 1/4" NPT plastic plugs in them. One is mid-log and the other 2 are only about 2" apart just behind the weld joining the tip to the round tube. All 3 are are on top, on the center line.

Why 3 and why nothing lower for a drain? I don't understand the locations.
I might understand the 2 next to each other if it's for pushing out water by using air pressure.. Adding low-pressure air to one would push water out a "dip tube" dropped through the other. Tipping the boat forward would allow the water to pool near the front weld. I would think a better location would be in the rear of the log.

The center plug location is weird. Are pontoon floats "rockered" so water would pool in the center of each log?

Many boats don't come with any plugs...I have 3 per side in strange locations.

[OK Toon]

Most likely your tubes are sectioned off. So each section needs its own plug. To get water out, you have to use a syphon tube. You just have to raise or lower the tongue of the boat on the trailer, to get the water to go to the end where the plug is for that section.

[emerald_coast_tooner]

On my Grumman logs the plug holes on top are blocked. There's seems to be maybe enough room for a straw sized tube. Need to figure out how to get water out.

[HandymanHerb]

Grumman usually don't have top plugs as they have an small open holes in the bottom of the compartment dividers that allow the water to run to the back plugs, but still trap air so they won't sink if you punch a hole in one of the pontoons

[emerald_coast_tooner]

this one does and they look factory...but that may not be the case.

[emerald_coast_tooner]

I found one of the top plugs was copper....yeah that's being replaced with a plastic one. Its also on the log that has the most corrosion.

[badmoonrising]

Copper +aluminum + saltwater =