Here's a short video clip of a basic test run of the replacement $28 12v dual drive gearbox coupled up to a pair of Floataboat Paddles. It's just a quick setup, so a squeak or two.
The rc tank gearboxes are not recommended, compared to this quiet and stable unit they sounded like chaff-cutters !
Check out the quick video clip. On 12 volts the paddles look like turbofans in a video even though just 150 rpm..
https://youtu.be/QtFFLHmcrpoThat's it on this Alexander Arbuthnot build until I clear up a couple of other, so far lengthy, projects.