In the diagram, the parts highlighted in blue can simply be coated with adhesive and bonded together. Once the hull sections are joined, apply a coat of clear varnish or waterproof sealant to the entire exterior to prevent water from seeping inside. As for the electronic control system, you can use a commercially available remote control; refer to the manufacturer’s instructions for operation, or feel free to leave me a message for further guidance.

Here is the link to purchase the remote control:

https://e.tb.cn/h.iMOnt6V1Bcr3jsB?tk=9ag555gxwJ7 MF278

Here is the link to purchase the underwater motor:

https://e.tb.cn/h.ioV5H3F1FFBtt0W?tk=n1Uc55gyuK7 MF278

The underwater motor can be directly inserted into the motor mounting holes on the hull and secured with bolts to prevent water from entering the interior. After tightening the screws, apply a layer of silicone sealant at the joints for added waterproofing.

For the power supply, a 8.4–12 V unit is recommended.