supply, and some will call or text message you if
bilgewater reaches a critical level. Such “extras” can be
useful, but it’s important to get the basics of a bilge alarm
right. After all, that alarm may be all that stands between
you and catastrophic down flooding.
Much like a bilge pump system, the wiring for a bilge
alarm must be virtually foolproof and failure-proof. All
connections should be made well above the maximum
bilgewater level or should be thoroughly waterproofed,
and the switch, regardless of variety, should be well
secured and protected from misplaced feet, gear, and
tools. Placement of the switch is critical. I’ve been aboard
vessels whose high-water alarm switch was more than a
foot above the bilge pump’s switch, which led me to
wonder, why bother with an alarm? My preference is for
the bilge alarm switch to be installed as close as possible
to the level of the conventional bilge pump float without
triggering false alarms. If that means the high-water
alarm switch is 2 inches above the conventional float
switch, so be it. If your bilge pumps stop working or
can’t keep up with a torrent, it’s best to know about it
as quickly as possible.
The audible alarm that sounds when high water is
encountered should be loud enough to be heard over
any other operating equipment: engines, stereo, TV,
and so on. And it should awaken even the soundest of
sleepers. I’ve been asked by some vessel owners to install
load hailer alarms on the weather decks so that if the
bilge floods while the vessel is unattended, there’s a
chance others will notice.
Bilge Pumps, Part II
High-water alarms, as well as bilge pumps, should be
tested after their initial installation and at least seasonally
thereafter. If you’ve never tested these systems (even if
your boat is new), you should do so right away. Testing
does not mean lifting the float switch; it means filling
the bilge with water until the bilge pump is activated
and pumps water overboard. Testing the system in
this manner achieves two ends. First, it gives you an
indication of how well, or how poorly, your bilge pump
system works. You’ll get a feel for how long it will take
to pump out the bilge. (If you’re curious, place a bucket
under the discharge, and determine how long it takes to
fill up. Then, do the math to determine the pump’s actual
capacity.) Second, it exercises the system and allows you
to see for yourself that it works properly, pumping water
or sounding an alarm as and when it should.
High-water alarms should be tested in a similar
manner. Shut off the bilge pumps and fill the bilge with
water until the alarm sounds. It should do so long before
water approaches critical mechanical or electrical
equipment. If you are unable to do this because water is
in danger of reaching batteries, flywheels, inverters, etc.,
then the message is clear: the high-water alarm float
switch is too high, and it needs to be lowered.
No bilge pump system is 100 percent effective or
reliable. There’s always a way to make it fail. I recall
one occasion of salvaging a cabin cruiser that had
been partially flooded as a result of a leaking seawater
strainer. After the water was pumped out, I inspected
the bilge pump system, expecting to find it improperly
installed or poorly maintained. In fact, it was a textbook
installation; I could find nothing wrong with it until
I noticed that a pencil had gotten stuck in the float
switch, jamming it in the “off” position. Remember that
bilge pumps are designed to contend with water—not
trash, dirt, or hair. The problem of grossly contaminated
bilges isn’t reserved for old vessels, either. The vast
majority of new vessels I inspect possess bilges that
are seriously contaminated with what I call new-boat
detritus, such as fiberglass shards, wood chips, wire ties,
crimp connectors, screws, and wire trimmings. All of
these items ultimately conspire to clog bilge pumps.
Take care of your bilge pump system, and it will
take care of you. Ensure that your pumps are installed
according to the manufacturer’s recommendations and
ABYC guidelines. Keep your bilge clean and inspect it
regularly, and you’ll have little to worry about where this
vital system is concerned.
Steve owns and operates Steve DA’ ntonio Marine Consulting
( www.stevedmarineconsulting.com), providing consulting
services to boat buyers, owners, and the marine industry.
