This 254 December 2015 video from Japan shows a giant squid swimming.
From VICE.com about this:
December 26, 2015 // 03:09 PM EST
The cephalopod was seen cruising Toyama Bay on Japan’s west coast, an area already known for its stunning firefly squid, which glow an iridescent blue and gather in the area to spawn. This squid, however, was an entirely different beast.