Put ESCs on a PCB

[AleksanderLidtke]

Put ESCs on a dedicated PCB to remove harness between them and the relays. This will reduce the mass of the ROV and make the assembly easier. Could use this IC from TI, or something similar (more research on components and prototyping are required). Possibly, use stackthrough connectors (e.g. Samtec's ESQ) to build a stack of boards like this:

[AleksanderLidtke]

Could even go flat-out and build a stack of boards for the entire ROV, connected to the Arduino as a shield. This would eliminate most of the harness, and make the craft smaller and easier to assemble.