We purchased the Arid Dry system for the following reason;
Bilge pumps are cheap and very effective for quickly removing a large volume of bilge water. Kind of like an Arnold Schwarzenegger solution to a very small problem, as the vast majority of boats pocket very small amounts of water at several different locations. Whether it’s a rubber lobe, a centrifugal or a diaphragm bilge pump, they all have a couple of things in common: They pump water, but are not designed to move air with the water. So, their efficiency drops dramatically, once air touches the pump. Obviously, they are not able to remove all of the water, therefore, the average pump will leave about one inch of water behind, when it cycles off. This is how they are designed and there is nothing wrong with your bilge pump, so don’t complain that there’s some water left as the bilge pump manufacturers will tell you that this is normal. The general rule seems to be that the larger the pump, the faster the flow, but this results in higher levels of residual bilge water. The smaller the pump, the slower the flow, with generally less residual water. Bilge pumps are best described as a safety product because they are able to maintain vessel trim and floatation, in the event of a failure that allows water to flood into your bilges. Every boat needs at least one operational pump on board before leaving the dock.
The Arid Bilge System, on the other hand, removes water slower than a traditional bilge pump. It is correctly designed and sized for the average daily bilge water that finds its way into the vessel.
Why: Instead of pumping the water, it suctions the liquids, similar to the common wet vac. The Arid Bilge vacuums residual bilge water with negative air pressure, and continues to pull the water even as air starts to move through the intake tubes. This system even pulls drops of H2O, bringing the bilge water level down to a sheen that evaporates completely dry within 20 minutes. The Arid Bilge pick-up sucker acts like a weighted filtered sponge, absorbing all of the remaining water down to nothing, directing it to the small capillary intake tubing for the trip to the central Arid Bilge unit, where the thinking is done inside the box. Here, the traditional float switch has been replaced with a pair of vacuum switches. These virtual float switches that never touch water, allow the microprocessor to sense the resistance created by the water, which is being pulled through the 20 foot minimum length of intake tubing. Once air is suctioned through the intake tubing, the resistance falls and the system will pause on that zone (or zones) for three hours, before resuming. If a larger volume of water suddenly enters the compartment within the rest cycle, the standard bilge pumps are there to prevent a more serious problem. The longevity of the Arid Bilge System, which uses mere milliamps, is enhanced by the fact that water never travels through the system’s vacuum pump, and never comes in contact with the virtual float (vacuum) switches. This is the right tool for the job, if you want 100% dusty dry bilges.
As to how does the water get in the bilge, for yrs I thought it was a leak due to rain.
Found out it was a leaking elbow for 1 of the engine strainer. For 10yrs. We were lucky it didn't turn worse but finding a leak there necessitated a repair on both strainers. I'm over-cautious, what I do to 1 side I do to the other.
Elbows replaced on both sides, no more WET bilge, it seems, but I still am not sorry to have a pickup in the shower sump. The Arid Dry has a pickup in both locations, bilge & shower sump.
While it only uses milliamps I still put an on/off switch in the installation. I'll use it when I feel it's necessary.
WET towels turn to mildew if not dried immediately. Towels need to be pulled from the bilge, dripping WET, thru the boat, to get to a point to wring out, so now there is another mess to clean up. Multiple trips are possible to remove an 1" of water. Towels are nice to dry you, but not so much the bilge.
The last thing to mention is will the DIY dry bilge product notice if you have oil or fuel in the bilge? Arid Dry can.
DIY is always DIY and not always engineered to be the best alternative, just the cheapest. I guess it always boils down to what is important, boat safety or saving a couple of bucks. That's my feeling anyway.