The issue with most 27-foot sailboats is they don’t have a lot of dedicated water stowage. The Catalina 27 has a 20 gallon water tank. Considering that the average family in the USA uses 300 gallons of water a day, we find ourselves in a problematic territory.
The “average family” only uses 70% of that 300 gallons for indoor use, which still leaves us with 210 gallons of water. Since we’re only talking about a couple, rather than the average family (3.13 people), that’s a kiss over 67 gallons a day per person.
There are ways to get by with less water. Use water sparingly, using seawater when possible, and being careful, one can get by with a couple of gallons per person a day. That gives us ten days of cruising until you need to replenish your water supply.
Suddenly that 20 gallon water tank is looking kind of meager.
Add a couple of small (2 1/2 gallon) Jerry cans plus bottled water as a fudge factor, and you’re doing great for coastal cruising.
What if you need to cross an ocean?
A small watermaker, though pricey on a VolksCruiser budget, is a possibility. Watermakers require power, which is problematic as well. Since a watermaker can fail, you still need to sort out a means of carrying enough water for your intended voyage.
I speak from experience. Being caught in a no wind situation for a couple of weeks will play havoc with your water supply as you drift towards the Caribbean.
If I were fitting out a 27-foot sailboat for an Atlantic or Pacific crossing, I’d add another twenty gallons of installed tankage. Then carry as much extra water in bottles as prudent. Providing I could deploy enough solar panels to run a small 12-volt watermaker, I’d consider a used one like the Power Survivor. I could then run it on solar for an hour to make a gallon of water a day.
As a side note, I keep thinking about the design of a small, AC-powered, DIY watermaker that could produce five gallons of water per hour. Powered using a 1000/800 watt generator that would be small enough to stow on a 27-foot sailboat would fall right into the Goldilocks zone.