Homemade Wireless MOB (Man Over Board) Device

By admin

In this post we face a FALL INTO WATER (MOB) sailing SOLO. We tested and demystified some of the traditional techniques to prevent and SURVIVE a man overboard. And above all we built ourselves a very simple wireless invention, for 25 euros, that stops the boat’s engine in case we fall into the water. All of that with plenty of testing, crashes, and good humor. Do not miss it.

We see several techniques, focusing first on avoiding falling into the water, through lifelines and a harness with elastic straps and a pair of carabiners to hook onto them.

I specifically use the following:
✅ Decathlon life jacket
✅ Elastic fasteners made up of: a hollow climbing strap with a shorter elastic cord on the inside and finished in two climbing carabiners. All sewn at the ends.
✅ Flat ribbon lifelines
🔵 You can buy them made https://amzn.to/3HF6K0Q
🔵 Or you can make them using, or better by sewing, double this tape: https://amzn.to/3zJVzSl

But what works best is a wireless man overboard device that can stop the ship.
You have commercials such as these:
🔵 ACR Waves Guardian €389: https://amzn.to/3Nx4wTg
🔵 Fell Marine MOB €260: https://amzn.to/3GZL5A9

Or you can build an equivalent one yourself for about €25 following the following scheme:

The material you will need to build it is the following, you can see how to do it in the video:

✅ Windlass remote control:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_AsrcSZ
🔵 On Amazon: https://amzn.to/3O2PNQ2
✅ Relay to activate with the command:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_9QeMuz
🔵 On Amazon: https://amzn.to/3HuPVpb
✅ A pair of delay relays:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_AWW5jn
✅ 12v buzzer:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_ANMmep
🔵 On Amazon: https://amzn.to/3mYpPBE
✅ Power switch:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_98T9FX
🔵 On Amazon: https://amzn.to/3mYkbza
✅ Some cables to tie it all together:
🔵 On AliExpress: https://s.click.aliexpress.com/e/_9iBrBr
🔵 On Amazon: https://amzn.to/3mYkbza

With all this you can build something like the following, if you order everything in a plastic box or a small tupperware:

With this and the output of the last of the relays, either using the COM and the NO, if what you need is to activate a button to turn off your motor, then you would put them in parallel to the button, OR the COM and the NC if what What you have to do to stop the engine is to cut the contact (in this case you would cut the cable from the contact and make it go through those two connectors.

If your engine, like mine, does not have an electrical stop and you have to pull a handle to drown it… You can also solve it with a line engine from the car insurance companies. Putting it in parallel in the place of the engine where the stall of the choke ends. The electrical schematic would be something like this:

You would need the following additional components:
✅ Linear closing motor:
🔵 On AliExpress https://s.click.aliexpress.com/e/_AUVgDP
🔵 On Amazon: https://amzn.to/3b8n7Xf
✅ Automotive relay, in case the motor is placed far from the rest of the circuitry, not having to use thick cables:
🔵 On AliExpress https://s.click.aliexpress.com/e/_AtXW1r
🔵 On Amazon: https://amzn.to/3mYX47C
✅ Automotive Fuse Holders, I use a 5A fuse:
🔵 On AliExpress https://s.click.aliexpress.com/e/_AOwDwV
🔵 On Amazon: https://amzn.to/3zRFFW2

And the installation would look something like this:

With the standard controller you can expect about 10 hours of battery life. So surely you want to buy many of these batteries: https://s.click.aliexpress.com/e/_AMGpXb
Although you can also replace the remote’s 12V mini battery by sticking it and connecting a battery holder for 8 AA batteries like this one: https://s.click.aliexpress.com/e/_A34fDR with which you will have guaranteed more than 200 hours of drums.