have had a few issues with the so called “waterproof
switch” for the electric bilge pump that I had installed in
my Mirage Sea Kayak. The rubber boot was broken, from doing cowboy
entries into the kayak, allowing salt water to get into the switch. I
have gone through two switches in six months and at $14.00 each it was
going to get expensive. Not only that, but the possibility of the
switch failing while I was on a trip when I’d need it got me
thinking of an alternative switch. I was also not happy with having
electrics in a place where salt water could get to them. I’ve
always thought of a day hatch as a place you need to be able to get to
on the ocean whatever the conditions.
answer is an Air Switch usually used in a spa pool to turn the blower
on and off. This comes in two parts, the plunger (190-0478) and the
latching switch (319-736). I sourced both parts from RS Australia an
online component store. By fitting this type of switch I was able to
keep all the electrics in a waterproof box in the rear compartment and
run an air tube to the box.
plunger was placed where the hole was for the electric switch. I used a
hole saw to enlarge the hole. Because of the curve of the hull I used a
small amount of epoxy glue to seal it off.
The 4mm air tube
runs through the rear bulk head to the waterproof box.
The only thing
I’d do differently would be to use a different box that didn’t need a
screwdriver to open it.
The box, showing the Latching air switch, with the 4mm air hose
view (complete with Daddy Long Legs spider)