George putting in place a new water tank vent system.

Issuma has nine stainless steel water tanks connected by four valves (several hundred litres in total). The vents for these tanks were all joined at the same level, then they went up to the deck. This seemed to cause a lot of confusion when filling the tanks, as water pouring out the vent hose was not an indication that the tanks were actually full. It meant only that one tank was full enough to overflow into the vent line and make the others appear to be full, and we would try to force water into the tanks under pressure until we guessed that enough was spilling out to indicate the tanks were likely full.

When we first filled the tanks, we stopped filling them whenever we saw water coming out the vent line. At the time, we did not realize this meant that we had not actually filled the tanks. On our first trip with Issuma, we were headed for the Azores (from France), but ran low on water after several days and went to Spain instead. We are hoping that this new water tank vent system, with each tank having a separate vent line will allow us to definitively know when each tank is full (the tanks do not have gauges and there are too many to want to install gauges). The vents are now inside the boat, close to where the water tank valves are, which should make it easier to check when filling the tanks.