As with virtually everything we use or do, there are good points as well as bad points. Using a purely Propel or CO2 system has a negative point in that the Propel or CO2 are stored in liquid form until the valve is opened at which point these gases ?boil? and become gas which then forces the water out.
Proper procedure when first putting your boat in the water means making sure the supply tank is full. The next step is to make sure the boat is properly trimmed when the ballast tank is full. Personally, I run my boats with approximately 1/4 - 1/2 oz of positive buoyancy. With a supply tank made of 1/2? copper pipe measuring 4? in length, capacity is approximately 1 3/4 ozs. of liquid. The final result is that if I use up all of the Propel, I will have in excess of 1 oz of positive buoyancy which means that the boat will come to the surface (with the motor shut off) whether I want it to or not. No, it won?t fully surface, but most of the sail is out of the water at that point and it?s a whole lot easier to recover a boat you can see. Of course, if the only problem is that you?ve run out of Propel, forward speed and up angle on the planes will get you to the surface and allow you to get back to shore, too.
This, by the way, is an excellent example of why the ?Hybrid? system is at least a step or two better than a pure gas system. With a high volume/low drain pump, you can surface all day long without changing the weight of the boat. But you still have the ability to surface if (when!) you find that one piece of monofilament or run through some weeds while submerged. Your Propel supply lasts a heck of a lot longer!
The U.S. of A - Land of the Free BECAUSE of the Brave