This video documents an ambitious mission to recover a lost submarine by designing and building a new, more advanced Remotely Operated Vehicle (ROV). The creator critiques the previous analog ROV, opting for a digital approach utilizing an Arduino with UART communication to significantly reduce tether wires (from eight to three, including video). Extensive bench testing confirms the digital communication and video signal integrity over a 60-foot tether. The new ROV design emphasizes compactness, brushless motors, lithium-ion batteries for ballast, and a pressure-resistant camera housing.
Initial dunk tests reveal buoyancy issues, which are resolved with added foam, and the ROV's basic maneuverability is confirmed. However, early lake searches with the ROV prove difficult due to poor underwater visibility and the ROV's inability to maintain a straight scanning pattern. A subsequent attempt with an expensive side-scan sonar also fails to detect the submarine on the lakebed, even after testing with a known sub. The project shifts to a GoPro-based scanning method using a makeshift raft, leading to accidental discoveries like a boat anchor and a false submarine recovery. Ultimately, the lost submarine remains unrecovered, with the search being prematurely halted by local authorities. The video concludes with the successful creation of a capable new ROV for future projects, despite the primary mission's failure.
Summarizing the Submarine Recovery Mission and ROV Build
0:01 The Mission Begins: The creator embarks on a "recovery mission" to find a submarine lost in a lake, acknowledging the previous attempt's failure due to unknown circumstances.
0:37 ROV Design Philosophy: The new ROV aims to be significantly improved over the "junk" old model, moving from an analog (relay-based) system with eight communication wires to a digital Arduino-based system using UART for only two signal wires plus one for video, totaling three wires for control.
1:36 Arduino & UART Testing: Initial tests confirm that UART signals and the camera feed can be transmitted without interference over a single cable, even when motors are active.
3:04 Full Tether Test: A 60-foot tether test is performed using a new Arduino Micro, successfully demonstrating motor control in both directions, validating the longer transmission line for UART data (as suggested by ChatGPT).
3:42 Compact ROV Design: The ROV is designed to be small and light for ease of deployment and double duty for boat inspections.
4:10 Watertight Bulkhead: A critical component is a brass-pin pressure bulkhead, sealed with superglue, epoxy, and Vaseline, designed for depths up to 50 feet.
4:33 Camera Housing: A tiny camera is mounted in a waterproof and adjustable case.
5:04 Final ROV Controls & Features: The ROV features dive, forward, turn left/right, and backup functions, powered by brushless motors and lithium-ion batteries (which also act as ballast).
6:02 First Dunk Test: The ROV initially sinks like a stone, but remains leak-free. Buoyancy issues are later corrected by gluing on foam.
6:25 Functional Testing in Water: After plugging in the video feed, the ROV demonstrates full functionality (diving, moving forward, spinning) in the test tub.
7:16 Video Interference & Speed Control: The video feed shows lines, potentially due to signal interference. The ROV's speed controller is initially tuned down, only utilizing a fraction of its potential power.
7:56 Pressure Test (Leak Proof): The ROV undergoes a successful pressure test by being submerged to the bottom of a pond for several minutes without being powered, confirming it is completely dry inside. It is verified leak-proof at 40 feet.
8:50 First Lake Scan (Challenges): The ROV performs well in the lake, but searching for the submarine proves difficult due to low visibility and the sub's unknown drift after being lost.
9:45 Odoo Sponsorship: The creator highlights Odoo project management software as a tool for streamlining complex projects.
10:38 Kayak Kite Scanning: A new "kite scanning" apparatus is built to drag the ROV underwater from a kayak, allowing it to "weather vane" with the movement, but visibility remains an issue at deeper depths.
11:16 Expensive Sonar Attempt: An expensive side-scan sonar, typically used by fishermen, is acquired to locate the submarine.
12:47 Sonar Limitations: Testing the sonar with a known submarine reveals it struggles to detect objects on the lakebed, rendering it ineffective for the mission.
13:54 GoPro Scanning & New Raft: A new inflatable raft (bought for $20) is employed for GoPro-based scanning, offering a more effective search platform.
15:16 Unexpected Discoveries: During scanning, the ROV gets tangled on an "underwater cable of doom," which turns out to be a boat anchor, valued at around $20.
16:09 False Recovery: A "recovery" is staged, where a different white submarine is pulled up, highlighting what a successful find would have looked like.
16:40 Mission Aborted: The search is prematurely ended due to intervention from "water police" who require the new raft to be registered.
16:52 Submarine's Fate Unknown: The creator speculates on the submarine's ultimate fate, acknowledging it might have floated up, been found, or truly sunk deeper.
17:22 Mission Outcome: The lost submarine was not found, but a much-improved ROV was built for future water recovery projects, despite the need for better scanning techniques.
17:48 Teaser for Next Project: The video concludes by teasing an upcoming project: a cardboard airplane.