Raincatching arrangements on AUKLET have developed further since the last post on this subject, that went up a couple of years ago ( ). Mainly, the process has become simpler, and in the average but not extreme rainstorm that we had last night and this morning it was very easy to collect about 5 gallons of water for drinking, washing, and plants. Here’s how it went:

A clean sheet of sturdy plastic, originally sold for putting underneath backpacking tents, was tied to the bulwarks in the cockpit, arranged to drain toward a low spot in the edge near the cabin. Sliding plastic tarp clips are really helpful with this – I’ve gotten them from Sailrite and also from a local “job lot” store in Holyoke. (Here’s an example, included for readers’ convenience. As always, I’m not receiving anything for sharing the reference: Without clips, it’s easy enough to scrunch a corner of the plastic around a small something, like a pebble or a bottlecap, and then to tie a loop of string where the plastic gathers.


Still, the clips are easier if you can get them, especially for adding tension along a side edge.


Some tarp clips require poking a hole in the tarp and using significant pressure to close the clip, which is then hard to remove. That kind is good for high strain situations, like winter covers for a boat. These others slide closed, requiring no holes, and can be slid open to move or use elsewhere.

The sheet of plastic in this system is about 4′ x 3′. You would think that it would be too small to do much, but in this past storm when the rain really dumped for a little while, the arrangement collected 1/2 gallon of water in about 10 minutes. This piece of plastic was in fact left over from other uses, but it was not dirty, and is now dedicated specifically for raincatching, carefully dried and stored between uses so that it’s clean when needed. Being on the small side has made it a lot easier to manage, especially because it can be pulled taut between the bulwarks.

In setting up the plastic it’s helpful to put a small carabiner on each string that ties off to the bulwarks, so the carabiner attaches to the tarp clip, or to the loop of string tied to a corner. This way the whole business can be set up while everything is still dry, and then part of it can be unclipped for access to the cockpit, without messing up the fussy adjustments that will make the plastic drain correctly. In the spot on this boat where the plastic sets well, the forward end of the mizzen sail would ordinarily overhang and drip into the raincatching project, complete with salt from spray and whatever else is in the sail and all its parts. That would be bad! Fortunately, the position of the sail and its lower reefed bundle is adjustable, so the sail can be shifted back and clear of the water operation. The small size of the plastic sheet also helps with sorting this out.

Originally I had the idea that it would be useful to have a drain fitting in the plastic sheet, which could have tubing attached that could then be led directly into a container or tank. A 1/2 inch plastic mushroom through-hull fitting from one of the boat catalogs worked easily for doing this. However, as it turns out it’s much simpler to just let the water run off the edge of the plastic into a bucket, and then to transfer the water from the bucket into storage containers. One reason for this is that it’s a good thing if the plastic sheet is low, so that it doesn’t catch the wind. Being low also means that tying to the bulwarks works out just fine. In the end, this brings the drain too far down to be convenient for much of anything. Having the drain in the plastic, without any tubing, has been useful for a little bit of weight, and for keeping the plastic oriented over the bucket – but I don’t think I’d put one in just for that!

Another reason for guiding the water into a bucket and then transferring to containers is that there are are inevitably little specks of who knows what that end up in the water. Using a white bucket, it’s easy to see these. They generally settle to the bottom, and it’s possible to dip the water out, or to carefully pour it off. Either way this leaves the specks at the bottom of the bucket, with that last bit of water that gets poured out or saved aside for washing or for watering plants.

I’ve been using square three gallon buckets made of food-grade plastic, found on the Internet. It’s helpful that they are white (for keeping clean), and also that they are square (for easier storage and positioning for water catching), but one could of course use anything, so long as it had not previously been used for chemicals. Tofu buckets from a local tofu maker come to mind as another possibility… It’s helpful that the rain catching container is not too tall, and that it holds a few gallons. One could use a cooking pot, but the tiny pot that I carry on the boat would involve a lot more tending. As it is, I slept through two or three hours of last night’s rain, and during that time the 3 gallon bucket filled to overflowing – I probably lost quite a bit of water, but since I got more than enough as it was, this was not a problem.

Then there’s the issue of getting the water from the bucket into containers. During the night I transferred a half a gallon of water into a gallon jug, and a little while after that completely filled a two liter drinking water bottle, both done by pouring the water out of the bucket, using a plastic funnel to get it into the jugs. Later, snug in my berth and listening to the rain, I was thinking about how to add a drain to the side of a bucket, with a tube for filling containers. This was to avoid lifting the heavy bucket when it was completely full. In the morning, with the overflowing 3 gallons and no such arrangement, it worked to use a small cooking bowl to dip the water out and into the funnel, and it was surprisingly easy to fill each bottle. I’ve now completely discarded the drain and tubing idea, because the simple version with the bowl was so easy and quick.


It’s been interesting to note the difference between using the plastic sheet, and simply setting out buckets. There are three of these square buckets on the boat, dedicated to rain catching. In an absolute dumping rain that goes on and on, it’s possible to collect about four liters (1 gallon plus) of water just by setting out the three buckets. In the storm that had that kind of haul, it turned out that nearby measurements said that there had been 4 1/2 inches of rain! On the other hand, I’m guessing that this recent storm had something along the lines of a half inch to maybe an inch of rainfall, and with the plastic sheet, not counting the probably substantial overflow that was lost in the night, I ended up with 5 gallons of water. This has convinced me to no longer bother with setting out three buckets, with the fuss of drying and storing them afterwards. From now on I’ll go with the plastic sheet with the one bucket, knowing that it will quickly gather a lot more water.

Following up on the post from a couple of years ago, the outcome of the fabric raincatching sheet, with the special funnel sewn into it, was that it was not practical, at least on this small boat, and in use in the damp north. Hung high enough to stay off the cockpit benches it caught the wind badly, flogging like a sail and needing to be taken down, and it was a production to set up, with a boathook set crossways as a spreader and tied to the mizzen mast. Being larger, the arrangement did collect tremendous amounts of rain – 12 (twelve!) gallons in the big storm where I first used it, and that in the time before the wind made it necessary to stop. The fabric funnel worked beautifully, but it was fussy to keep the attached plastic tubing where it belonged, as the fabric lifted in the wind. In lighter rainfall, a good bit of water went into soaking the fabric, before any was actually collected. In either case, afterwards it was hard to dry the fabric properly, and even once dry, because it was cotton it tended to collect the dampness while stored. In the end, mildew was a problem, and I started working with the plastic sheet.

The other thing I’ve learned in the intervening time has to do with using rainwater for drinking. Basically, rainwater is distilled, with no minerals. Although there are holistic healthcare practitioners who recommend drinking only distilled water, there are also reports that doing this, whether from mechanical distillation and bought at the store, or from rainwater, can lead to health problems. Supposedly these issues mostly involve loss of calcium and other bone and teeth minerals.

The permaculture folks who are raincatching for drinking water suggest that putting crushed oyster shells in the bottom of the water container will take care of this issue, as the water will leach minerals from the shells, rather than later from one’s body. I’m looking toward doing something with shells, but haven’t yet. I’m assuming that broken up clamshells would work just fine, but I’m waiting for the opportunity to collect some from a clean beach. Lately I seem to be spending a tremendous amount of time in areas where the water is working-harbor brown, which has hindered this particular task. Since the boat water supplies alternate between rainwater and wellwater from shore, and I ordinarily take calcium/magnesium supplements, I’m hoping for the best, sans shells. In the meantime, the rainwater tastes great, and definitely feels better than anything from a chlorinated municipal supply.

So that’s the latest on raincatching. This recent effort is the easiest it’s ever been, and it feels like the system is a keeper. It’s a great thing to have the water supplies all in order, without any outside assistance. Now I’m inspired to get back to growing more vegetables…


[Written about a week ago; now it’s been sunny and hot for days…]