Getting Started

This page takes you from an unopened box to your first recorded measurement. Read it once before you go out — two of the steps are easy to get wrong on the water, and both are called out below.

What’s in the box

The complete kit. The tube on the left holds the green drogue; the one on the right is only a holder.

• DrifterBuoy CMU-30 unit
• Two tubes: one is just a holder, the other contains the green drogue
• Mounting screws — these are supplied inside the instrument
• A thin safety cord
• USB charging cable

Fit the drogue

The green drogue is what makes the buoy follow the water rather than the wind. The buoy will not measure current correctly without it.

1. Take the green drogue out of its tube. The plain tube is only a holder — there is nothing to fit from it.
2. Take the screws out of the instrument.
3. Screw the drogue onto the bottom of the instrument.

The drogue fitted to the bottom of the instrument — this is what it should look like before the buoy goes in the water.

Fit the safety cord

Run the thin cord under one of the screws as you tighten it. If the white part ever snaps off at its base, the cord is what stops the drogue from being lost. Fitting it takes ten seconds and it is the difference between a broken part and a lost one.

Mount the tube on the boat

The plain tube is the buoy’s holder on board. Fitting it to the boat means the buoy has a fixed home between measurements, instead of rolling around the deck.

The tube mounted upright on the console of a RIB, within arm's reach of the helm.

Mount it where you can reach it from the helm, upright, and with the buoy’s handle at the top so you can lift it straight out with one hand. On a RIB the side of the console works well: it is solid, out of the way of the tubes, and close to where you stand.

Keep the retrieval line coiled next to the tube rather than in the tube, so it runs free when you drop the buoy.

Charge the unit

The unit charges over the connector on the housing. In normal use it needs charging roughly every three to four days — how long a charge lasts depends on how much you measure, so let your own usage set the rhythm.

Always close the connector

Close and seal the charging connector before the buoy goes anywhere near water. This is the one step that turns a wet buoy into a dead buoy.

Controls

The housing has two controls and one connector:

The charging connector, on/off button and function button on the yellow top deck.

Control	What it does
Power switch	A latching switch. Press it fully in — if it stays down, the unit is on. Press it again to switch off.
Button	Starts a measurement, and stops a running one. Hold it rather than tapping it.
Connector	Charging. Keep it closed whenever the unit is not on the charger.

Switch on while still on shore

Do this before you leave the dock

Switch the unit on once before you set off. The first GPS fix after a big change of location can take one to two minutes, and you do not want to spend that time drifting past the spot you meant to measure.

Hold the unit to your ear — a quiet two-tone beep tells you the fix has arrived.

Connect your phone

The buoy runs its own WiFi network. There is no internet on it — it only serves the buoy’s own pages.

1. On your phone, find the WiFi network FASTRRR-DRIFTER and connect to it.
2. Enter the password: sailfastrrr
3. On most phones a window opens by itself showing the buoy’s page, the way airport WiFi does.
4. If it does not, open a browser and go to 192.168.1.1

On iPhone

Because the network has no internet, iOS may need a few attempts before it sticks, and it will ask you to confirm that you want to stay connected without internet. Accept that prompt — otherwise the phone quietly drops back to mobile data and the buoy’s page will not load.

The WiFi name and password are set per device and can be changed on the SD card, so a buoy configured for your fleet may use different ones.

At most two phones or laptops can be connected to the buoy at a time. If your phone cannot join, check whether two others are already on it.

Run one measurement before you deploy

Try a full cycle on shore, watching the page on your phone. You will see the buoy move through four stages:

1. Searching for GPS
2. Deploy countdown — the grace period to get the buoy into the water
3. Measuring
4. Measurement finished — the result appears

Once you have seen that sequence on dry land, you will recognise it on the water. The Web Interface page shows each of these screens as it appears on your phone.

Deploy

Start the measurement, drop the buoy in during the deploy countdown, and let it drift. The measurement stops on its own when the window ends.

Stopping early invalidates the measurement

If you lift the buoy out before the window closes and stop the measurement, the result is marked invalid. That is deliberate — a shortened drift is not a measurement of the current. Let the window finish whenever you can.

After a measurement the buoy is ready for the next one straight away — there is no need to switch it off and on again.

Next steps

• User Guide — the measurement cycle in detail, reading results, settings and logs
• Troubleshooting