Hey Bill,
That looks fine 
It’s understandably not supposed to “function” like that. Our support team mentioned a few hours ago that there have been a small set of similar cases that have been related to what might be a previously unknown failure mode of the Pixhawk. Given your setup looks fine I’d recommend you send an email to support@bluerobotics.com so you can discuss if it’s the same issue, in which case they can either send you a replacement Pixhawk or set of lights depending on which one’s actually faulty
Yep, they can at least go in the first three AUX ports, you just need to make sure the yellow wire is at the bottom (not the top), and set the Channel appropriately (8 MAIN + x AUX) on the lights page. My above recommendation still applies, but it wouldn’t hurt to see if using a different port fixes the issue
Haha, we wish. The flight controller (Pixhawk) has an Inertial Measurement Unit (IMU) which measures acceleration in and rotation about all three motion axes (which is used in the Stabilize and Depth Hold flight modes). Acceleration measurements can be integrated to give a velocity estimate.
Unfortunately acceleration data isn’t amazing for estimating position. While it’s possible to integrate twice to get a position value, the resulting estimate drifts quite significantly over time, especially at turns, so isn’t suitable for navigation purposes.
Normal GPS doesn’t work underwater, but there are alternatives available. If you’re interested in underwater positioning I’d suggest you take a look at this thread, and possibly branch out into some of the topics that are linked just below the initial post
I added a positioning tag yesterday, so there will also be some interesting posts there, but I most likely have missed several of the older useful ones.
No worries, great to hear!