Edit: Sorry, I am dumb and completely mixed up satellite systems, and only caught that after the upload. There's no way you can see submarines with Landsat, but you can with Sentinel imagery. Landsat is old school, Sentinel is the newer platform, which you can find here: https://www.sentinel-hub.com/explore/sentinelplayground/
It's better to download the imagery you want, but for a quick peek from a web browser, the Sentinel Playground works great.

Also the freqs I mentioned that are worth monitoring are below:
BearNet (and other) freq: https://www.numbers-stations.com/russia/russian-air-force-stations/
US HF-GCS: https://www.numbers-stations.com/usa/hfgcs/

00:00 - Northeast Region
07:15 - Southeastern Region
17:14 - Zero Trust Infratructure Building
26:24 - Transnational Repression
31:06 - East Central Midwestern Region
34:20 - Southwestern Region
39:42 - Western Region
44:41 - The Far East
01:02:48 - Closing Thoughts