It doesn't matter much if you only ever want to poke around in a swimming pool or very shallow stream like shown here, but if you get into this hobby and ever want to run in deeper water without a tether (whether autonomously or acoustically) you'll either want it to be positively buoyant or have an independently powered emergency surfacing mechanism (eg. drop a weight).<p>Otherwise if you lose power or control you will lose your sub.
I've watched the BrickExperiments YouTube channel, but I always assumed that the channel was drivel, and that much like social media of today, the details of the build would be omitted, and lost forever- but this changes the game for me.<p>A 10 part post is beyond what I'd consider most 'good' creators to put together. The author is obviously technical, and is wise to the nature of the videos. I'm impressed.
Some might find the system by James H. Rogers, developed in the era of World-War-One of interest. The late T.E.Bearden claimed that Rogers system was rediscovered and 'lost' at least seven times from then until our times.<p>"James H. ROGERS
Underground & Underwater Radio<p>( Static-free Reception & Transmission Underwater & Underground )"<p><a href="http://www.rexresearch.com/rogers/1rogers.htm" rel="nofollow">http://www.rexresearch.com/rogers/1rogers.htm</a>
As an EE for an ROV manufacturer for 20 years, this was really interesting to see how he attacked some of the design issues that plagued my entire career. Great stuff!