I was looking at this back around the Nord Stream stuff.
You can get off-the-shelf small UUVs for like $30k that you could use to plant explosives from a boat.
It's actually a real issue for pipelines, because there's essentially nothing by way of treaties protecting them. Companies just kind of started building them, and nobody has really gone about methodically attacking them yet.
For cables, there's some treaty from the late 19th century, I think signed in Paris, that covers them. Which some countries have signed.
I always hear about how cheap and easy it is to buy aerial drones, but really nothing about UUV's.
$30k seems doable for the Houthi, but prob not something they could mass replicate. And they're pretty limited as to which sections of the pipelines are viable targets.
googles too
I found a small one for $5600 with a 330 ft depth rating. It's tethered, but you could prob extend it:
It is wild how exposed the pipelines are, and there's MILES upon MILES of them. I guess people figured their depth would protect them... But tech keeps getting cheaper, more capable, and more accessible ¯_/(ツ)_/¯
Keep in mind that it's not just reaching the depth -- that you gotta have the payload to haul an explosive package and at least enough manipulation ability to place it, and I don't think that that $5k UUV has any manipulation capability, from a quick glance. Though the payload issue isn't large, if you're gonna rely on a tether, are willing to wait, and are willing to make your explosive package roughly neutrally-buoyant.
But, yeah, in terms of vulnerability, a $30k or $5k UUV, generally-available to the public, is more-or-less identical -- like, there's no real bar to getting either. And I can imagine that $30k definitely isn't the lowest out there.
It is wild how exposed the pipelines are, and there's MILES upon MILES of them
Yeah, I dunno how you'd counter it. You could have sensors and some kind of counter-UUV system down there permanently, all along the length of the thing, and at greater cost, that could maybe stop one UUV and warn authorities of trouble at that point, but I don't know whether that could be combined with other capabilities to translate into an effective defense of a whole pipeline/cable.
In WW2, we defended convoys, but that was a single point, not something always spread out along the whole ocean.
It's especially an issue for Europe, which has a lot of submarine infrastructure in shallow seas surrounding the continent. If the EU could get their politics together, they could probably do the equivalent of eminent domain, cut infrastructure corridors overland, but links to Scandinavia, the British Isles, and Africa are still gonna be submarine.
Maybe some sort of cheap buoy network outfitted with sensors, GPS, and a longterm sustainable power source
Idk how feasible that would be and can't even estimate how many buoys it would take to cover everything
But you could anchor or even connect some of them directly to the pipeline itself. If it's a network, having every few buoys connected via fiber optic to the pipeline would allow them all communicate and transmit data fast af
Might be possible to collect submarine comms too if the tether acted like an antenna haha
Regular bullets fired out of regular firearms basically disintegrate in water. Counter-intuitively, putting more energy into a bullet only worsens the results, making it stop even faster.
Underwater firearms do exist, but they are not common, and even they have incredibly limited range. As far as I know, none have effective range greatly exceeding 50 meters, let alone 100.
Looks like Russia made one during the Cold War for frogmen firefights (<-wild) At a depth of 15 ft, its effective range was 99 ft!! The deeper you go the worse it gets though, and it totally sucks on land too
Every source I can find mentions maximum effective range at 15ft to be ~98 feet, not 909. So that zero in the middle is probably a typo, if I had to guess.