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I'm using a Ubiquiti Nanobeam to connect my home's LAN to a dock around 800 feet away. The dock's Nanobeam will be mounted on an isolated piling that is 10 feet away from the rest of the dock and is in about 15 feet of water. So, the cable will be run through roughly 40 feet of brackish water. (15 down, 10 across, 15 up)

On Amazon I found an ethernet cable that's rated for outdoor use- here's their picture showing the "outer jacket" that makes that possible:

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Does this mean that the cable is waterproof? Could it be possible to run this underwater? Both of the ends of the cable will not be near any water, of course.

fixer1234
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Ladinn
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3 Answers3

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As someone who has worked with buried and submersible cable under various conditions like rivers, lakes, ponds, etc. and at marinas, I would not recommend normal "outdoor cable" be used for any submerged application, the chances of damage to the cable is too great and the outer shell will deteriorate quickly. I would recommend a shallow submersible grade cable, like Belden Waterdog or Falmat DS-Xtreme, or if that is out of your budget a gel-filled direct buried cable would likely suffice such as this https://www.amazon.com/Vertical-Cable-Filled-Flooded-Ethernet/dp/B005EV2A4E as an example only, any decent quality gel-filled Direct Burial CAT5E cable (sometimes called "flooded" cable") should work for this application.

acejavelin
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All outdoor cable is water resistant to a degree. However when you are talking about submerging a cable, this is an entirely different matter than being exposed to rain/dew.

When you are going to be submerging a cable, it needs to contain some sort of "waterblock" that will prevent the water that eventually gets through the jacket (and it will, guaranteed). Waterblock comes in two forms, dry or gel.

Dry waterblock is a "fabric" that lines the cable under the outer jacket and surrounds the inner core. When exposed to water it will swell and block any point where water gets through the jacket. Dry waterblock is easier/cleaner to work with as you simply cut away the waterblock that you don't need when terminating.

Gel waterblock fills the entire inside of the jacket and will settle to fill any gaps or openings that would otherwise allow water to penetrate. It is generally harder and messier to deal with than dry waterblock. You must remove the gel before termination as the gel is non-conductive and the gel can get onto hands/tools/clothes and nearby objects while you are working with it. However, gel provides a much better waterblock solution and tends to provide a longer lifespan for submerged cable.

Either way, you also want to get an outer jacket that is at least UV-resistant (i.e. so sunlight is less likely to weaken the material) and if possible corrosive resistant.

YLearn
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Found the answer here.

"Special exterior waterproof direct burial CAT6 cables should be used for outdoor runs instead of ordinary CAT6. Direct burial CAT6 cables cost more, but they are designed specifically for outdoor use. Exterior-grade Ethernet cables are waterproof and do not require conduit. They can be buried directly in the ground. If you aren't burying the cable, choose a waterproof Cat6 cable that has a UV protective jacket to prevent damage from sunlight exposure."

Edit: Per @acejavelin's comment, I'll be using a gel-filled cable:

"As someone who has worked with buried and submersible cable under various conditions like rivers, lakes, ponds, etc. and at marinas, I would not recommend normal "outdoor cable" be used for any submerged application, the chances of damage to the cable is too great and the outer shell will deteriorate quickly. I would recommend a shallow submersible grade cable, like Belden Waterdog or Falmat DS-Xtreme, or if that is out of your budget a gel-filled direct buried cable would likely suffice such as this amazon.com/Vertical-Cable-Filled-Flooded-Ethernet/dp/B005EV2‌​A4E"

Ladinn
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