Just wanted to share my last few weeks "playing" with Insta360 as a company and their One X2 camera.
If you don't want to read this, here's the lowdown:
Use a waterproof case before you hit the water.
Don't be surprised if you find the camera unreliable.

I ordered the camera on their website and the camera that came in was dead on arrival: It would freeze when connected to their Insta360 app and wouldn't record. After 2 weeks of back and forth I got an RMA and they sent a replacement camera.

I received the replacement camera and took it for a spin on the water (on 3/3 and 3/11). I then noticed the camera wouldn't come back on after each session. I managed to turn it back on once but now it is definitely dead again.

I thought that water might have entered into the camera, but I couldn't find traces of water or humidity inside. I contacted their customer service again and after a phone conversation and me returning requested photographic evidence, their phone number is now saying "the number you have reached is not in service" and I cannot get anyone answering my emails anymore. Did that company go bankrupt?!

Anyhow, here is my guess: The engineering of the USB port waterproofing gasket is a very thin and weak rubber bead 1/32' wide and 1/32" deep. The camera entering in contact with water at a fair amount of speed might get that seal to fail because of the extra water pressure. The camera is advertised as waterproof up to the depth of 10 meters) and I think it probably is true but in a static situation.

Long story to say that the camera can do cool videos, but the engineers didn't understand what waterproofing is in context of designing an Action Camera for watersports! Lesson: If you get one, also get a waterproofing case!

Similar experience with mine, it worked GREAT for a while, and then on a work project where I was working aloft in some very windy and cold conditions it kept shutting off when I really needed it to work. It was handheld so I could restart it but a real pain in conditions where I did not want to be messing with my gear. I had paid for the extra warranty on it, and even so had pretty much threaten the email agent as they wanted me to do all sorts of hoop jumping to prove the camera was bad. They said water intrusion but did send me an entirely new one. This one has been good but I'm always careful to close the door all the way now. I should be using mine but broke my harness mount carbon tube hitting Wisconsin last fall and haven't gotten aroudn to making a new one. My GoPros have been very reliable so hopefully they come out with a good 360 camera and upgrade their software a bit, as it's quite cool technology. I like having it on projects at work as I can zoom in and out and don't have to aim a camera for reference video.

Yeah, the door design is really bad. They need reengineering!
Insta360 finally replied and sent an RMA. I sent them the dead one and If they "think" the issue is from misuse and not from hardware failure, they'll send a new one, otherwise I'll have to pay for repair if repairable (probably swapping the PC board) ...And I don't know if not repairable!
Anyhow, if I get a new one, I'll put a dab of silicon sealant over the USB port (don't need it) and will tape the battery door with electrical tape every time I'm going on the water!
BTW, the waterproof case is only good for underwater footage: The bulbous plastic case in front of the lenses is outputting too much glare and ruin the footage when shooting out in the air from what I heard.

While I'm glad they're moving through a process, that is what happened with me as well. They did eventually replace the entire camera which was cool as it gave me an extra battery from the old one, but I thought the process kind of stunk considering it was water damage on a waterproof product. The process was moving so slow that I ended up buying a GoPro 11 as I needed it for work.I'll also add that the lens covers which they advise for this sort of thing are not that great for on the water, they allow water and condensation in between the lens and the cover, which naturally turns to fog as soon as the Sun hits it. Knock on wood I haven't had any issues with bare lenses.

For as commonplace as this kind of video has become, it's important to remember we're still on generation 3 or so on most of these devices. I'm really hoping they get more robust and appropriate for all the cool things that people do in the commercials for them.

I received my 3rd Insta360, second replacements under warranty. 1st camera was defective on arrival (connectivity problem), the 2nd took 2 windsurfing sessions until water got in and destroyed it, and finally the 3rd one seems to be working but I’m taking a preventive measure against shoddy engineering by tapping the doors with good old 3M electrical tape.
Hopefully that should help but let’s see where the damn thing will let water in this time! Ive seen complaints about microphone holes that might also be the issue…
This camera is rated fully waterproof to a depth of 10 meters! Clearly not the case looking at how many people are complaining about this issue online.

Some might ask “why bother?”. Good question. I can’t be defeated by a stubborn product. We’ll see who’s more stubborn!

BTW, insta360 just released the fourth version of that camera and the waterproofing issues didn’t seem to be part of the improvements: the troublesome design of the battery and USB doors is the same as before!

Dang, you've got rotten luck with those. My replacement camera is still working and super useful at work where I use it to get images/video of tough to access spots like in this pic where I needed details on the top of the rig and my head would only get so high up.

For the Insta360 I really like the harness mount best, I think Greg you gave me the idea for that. It's just a splash of fiberglass on the back of my harness (taped to keep it from sticking) that gets bolted through the harness itself. The splash as a socket to accept a carbon tube with a 1/4 -20 stud bonded in. Works great although it did not survive the time I grounded out at Silver and came up with sand in my mouth.

Always wanted to try the top of the rig, could probably slide a thinner carbon batten or dowel into the sleeve over the mast cap.

Stealing your tape idea, doesn't seem like it could hurt and probably helps!

Yeah, I haven't explored the harness mount yet but that's pretty cool. Really looks like a drone flying next to you!
As far as my tapping experiment goes, it looks like it's a success! No water in the camera and it is fully functional after being in the water a few times. It's an extra step to do but at least it saved me from claiming warranty over and over. We'll see how long it lasts until I screw up the tape installation or I get bored doing it!

Here's a bit of jibing action at Pike Lake on 4/22. On-off conditions: 12-15kn gusting 30kn in an instant! 6.2 was the weapon of choice for some fun speed runs!