The BilgeWatch 8 Bilge Pump Activity Monitor is an aid to Marine safety. The BW8 will monitor and record the activity for 1 to 8 bilge pumps
Bilge pump activity monitor  
Frequently Asked Questions regarding the BilgeWatch 8...
Welcome to the BILGEWATCH 8 Frequently Asked Questions. Below, we have tried to answer the most common questions visitors to our Web site may have. If you find that your question about the BW8 is not answered on this page, please click here to ask a question.
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Can the BW 8 be fitted to any boat?
Answer: Sail or power, if it floats and has 12-24v DC bilge pump(s), with automatic operation by a float switch (or similar) and has a dry location to fit the BW8 then the boat is suitable.
Click here to view typical wiring
I only have 2 pumps to monitor, is this okay?
Yes, the BW8 will monitor any number of pumps from 1 to 8
I'm thinking of buying a BW-8 for my boat, is it easy to use?
The BW 8 is user friendly and very easy to use, the handbook has simple step by step instructions for each operation. Click here to download the BW8 handbook.
For a virtual "hands on" try before you buy, download the BW-8 simulator Click here for BW8 Simulator.
How much power does the BW8 use from my boats battery ?
An insignificant amount, the BW8 needs only 3.2 milliamps (0.0032 Amps) from either 12v or 24v systems while monitoring. This will increase to 60 milliamps (0.06Amps) only when the backlight is on (set at full brightness), the alarm and alert outputs can also supply up to 50 milliamps (0,05Amps) each giving a maximum of 160 milliamps (0.16Amps).
Give me a practical example to show how the BW-8 can help me?

Your boat is moored at a marina and during the winter, you check on it about once a month. On each visit, the BW-8 shows that the engine compartment bilge pump has operated once or twice for a short period, not enough to set off an alarm. The boat has twin shafts and you assume the bilge pump activity is due to the stern glands. The fact that the recorded activity is consistent and minimal is reassurance that the leak is not worsening. The rest of the boat is dry.

On one of your regular visits, you find that pump 4 in the forward head has operated once. Unusual, you think. But you assume that some rainwater from a recent storm had found its way in. You decide to ignore it. On the next visit the BW-8 shows that pump 4 has been on twice. Again you come up with a logical explanation (after all, the forward compartment is awkward to access). Again, you ignore it.

On the following visit, the BW-8 shows that pump 4 has operated 5 times. Now, you have real concerns and no justifiable excuses. You must check it out. Inspection reveals that a skin fitting is weeping a steady trickle of water into the bilges! You organise a lift out with the marina.

While replacing the skin fitting you notice that the 1/4" (6mm) mounting bolts have eroded to about half their original size and you realise that before long the weep would have become a torrent when the fitting came off completely leaving a 2" (50mm) hole, 2 feet (600mm) below the water line. That is close to 3500 gallons (15000 litres) per hour of water coming on board; assuming a 500 gph pump (ignoring any depreciation for head), that's seven gallons in for every gallon that the pump can get out!

The reason for the eroded bolts? Yes the sacrificial anodes should have been replaced last season! (For eroded bolts try substituting, Perished hoses/caulking, cracked skin fittings/hulls, badly fitting hatches etc, etc.) JUST AS WELL YOU FITTED THE BW-8

How should I use my BW-8 when I'm on the boat?

If a pump becomes active, the backlight will illuminate. The active pumps are displayed in sequence with the run time for each shown in minutes. Getting a feel for each pumps activity pattern under different boat operating conditions, will give an early warning of developing problems.

Watch out for extended run-times or increased activity - either could be a sign of a leak that is getting worse. Remember, if the inhibit option is activated, the BW-8 will display, but not record pump activations.

How do I use the alarm delays?

An ALARM output delay can be set for each pump:- "OFF" (no ALARM output trigger), "ON - 00" (instant ALARM output trigger) or "ON" + a delay time of:- 1 to 10, 15, 20, 30 or 60 minutes. Set the delay time to suit your boats specific requirements and safety needs.

If your boat is normally dry, low delay settings will suffice. If you have an area of the bilges which has a known acceptable water intake, set the delay for the pump that serves that area so as to avoid false alarms.

How do I interpret the data?

The BW-8 will show the complete log of pump and ALARM output activity for the current period. By comparing the number of pump activations and ALARM output activations with previous periods, taking into account the length (DAYS count) of the periods being compared, increased activity trends can be detected.

It is recommended that you store the current data and start a new period at regular intervals, from one week to three months.

My BW-8 shows more alarms than activations. How is this possible?

It's not very likely but, this could happen if a pump is active when the inhibit is switched off, the activity will not have been recorded but, if the pump stays active and exceeds the set alarm delay, the alarm will be activated and recorded.

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The BW8 Bilge Pump Activity Monitor is an aid to Marine safety