This is something I picked up. This is apparently one of the most famous videos of a nuclear bomb test. Apparently this nuke was an UNDERWATER one (that's important), apparently below the surface of the water, underneath a barge. This footage is so famous that it's actually played multiple times in the 'Dr Strangelove' final nuclear apocalypse scene.

Watch this video first: https://youtu.be/MWBMImBA6jE

In this video above, it looks like it's footage of something that has been publicly aired on TV or in some sort of video. Notice that there's a jump in the first few seconds of the explosion. This is important. Whoever published\aired this video has deliberately cut the very first second or so, the initiation of the explosion from the footage. In this way the footage looks much more convincing as some sort of super scary 'super weapon'.

However other footage of the same detonation exists elsewhere. Here's another video: https://youtu.be/YUd7tgIirBI

Now if you watch this video, you can clearly see that the initiation of the explosion starts ABOVE WATER, on the barge itself, as if the barge has been packed with explosives. But they claim that what we're watching here is a nuke detonating UNDERWATER. You clearly see a bright flash of explosion, so bright that there's a reflective flash on the clouds above. You don't see any 'flash' below water, just an explosion that seems to be directed upwards from the barge, as if they were trying to draw water into the air with the explosion.

No matter how many times I watch this, I can't unsee that the explosion takes place either entirely or almost entirely ABOVE WATER.

If a nuclear bomb detonated below water, in theory the initial reaction should be so intense and hot that it should literally BOIL water. Yet all we see is this above surface explosion.

This explains why the initial flash\explosion is missing from the Dr Strangelove Sequence and the first video link I've posted.