Our Raw water alarms are used on Tugs working the
Panama Canal

Quickly detects loss or restriction of raw cooling water.

Three Models to Choose From


ABYC: “P- Requirements for Wet Exhaust Systems-2002
An indicator shall be provided at all helm positions to indicate
loss of exhaust system cooling water supply"


$79.00 BUY NOW >>


$149.00 BUY NOW >>

Singe (2.5” x 2.5”) and twin alarm panels (2.5” x 3”) with sonic and red LED visual indication. Flush mount, requires 2" dia. cut out. Single supplied with one band sensor, Twin supplied with two band sensors.

Raw water failure is the most common problem with marine engines. Within a short period of time several thousands of $$ in damage to engine or wet exhaust system can occur.

All our systems consist a fast acting thermal band sensor that quickly detects loss or restriction of raw cooling water well before engine over heats or damage to wet exhaust components. Nylon coated stainless steel band senor fits wet exhaust hoses from 1-3/4” ” to 7” in diameter. For larger diameters use extension kit below. Standard tinned copper sensor cable is 10ft long. Call for longer cables or see Wiring Accessories below.

By the time engine over heat alarm activates, damage may be already done.  This piston soft seized, breaking two compression rings.  After a costly repair this customer now has one of our Raw Water Failure alarms on his vessel.

Another melted muffler


A few seasons ago the sea strainer on our fishing charter boat clogged with kelp.
The result was a burned up wet exhaust system that almost caused the lost of the boat.
After thousands of dollars in repair and lost revenue from down time, we added a Borel raw water alarm to the new installation.

This season we experienced the same problem, sea strainer clogged with kelp.
The results however were quite different. The raw water alarm when off so fast we had no damage to engine or exhaust system. Even our raw water impellor was saved. After cleaning out the strainer, we were on our way. All of our charter boats are now equipped with this alarm. I highly recommend this product.

Capt. Joe. K.
Eagle Charters, Elfin Cove, Alaska


I purchased an exhaust alarm from you two years ago, and just wanted to let you know it finally paid for itself, and many times over! I've posted the story on my blog, click here.

Gerhard M. S/V Sunny Spells, Australia


I received the alarm very quickly and have it fitted. It works great and is admired by other boat owners. You should be getting more orders from Ireland!

Paul L. Ireland


I intalled the Borel alarm after the mixing elbow and forgot about them. 4 months ago while cruising, it went off. I shut down immediatly and come to find out, the impeller went. I never heard a peep from the engine overheat and no harm was done. I wouldn't run a diesel without them.

From Luhres Owners Forum

(Click here for other customer comments.)

(Click here for what we have learned from our customers.)


Following excerpt is from Passagermaker Magazine May/June 07
Written by: Steve D’Antonio Vice President Zimmerman Marine
Technical Editor Passagemaker and Ocean Navigator Magazines.

If you’ve never experienced an overheated engine, you probably haven’t been boating long enough. As the manager of a busy boatyard, I see the results of overheated engines and gensets all too often. Shouldn’t the overheat alarm tell you when the engine is overheating? Yes, but by then, more often than not the damage has been done.

Fortunately, there is a solution to this problem. Borel Manufacturing offers a device that quickly identifies a rise in wet exhaust system temperature before damage occurs.
Their Raw Water Failure Alarm is simple, straightforward and easy to install.
It utilizes a small, highly sensitive temperature sensor switch that is strapped to the exhaust hose. If the temperature exceeds 165F (well within the exhaust hose working temperature range) the alarm sounds, and the operator can shut down the engine before any harm is done. It does not matter where the water failure occurs- the intake, raw water pump or exhaust injection hose.

A boatyard technician installed Borel’s Raw Water Failure Alarm in just a few hours aboard Growler. (36ft lobsterboat owned by Bill Parlatore Editor in Chief of PM Mag)
The Borel alarm will work with any wet exhaust propulsion engine or genset.




95dB horn with visual indication, weatherproof. Flush mount, requires 2" dia. cutout. Measures 2-1/2" X 2-1/2" X 2" deep. Ideal for flybridge


95 dB horn with two visual indicators. Can be connected to two alarm panels for twin engine or main engine/genset applications. 2” dia cutout. Measures 2-1/2" X 3" X 2" deep.


Optional Band Extension Kit.
Up to 14" Dia.

BUY NOW ONLY $5.95>>

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