Inadequate water tankage will limit cruising plans
Inadequate fuel tankage will make some destinations unreachable with safety
Tanks in most boats cannot be easily removed, a major headache long-term
Fuel and Water Tanks
In addition to the amount of fuel or water a tank will hold, the placement of the tanks in the hull is also critical
Putting tanks up in the bow or far aft will create trim problems as the levels and weights change through usage. The fuel and water tanks in Shannons are all placed low in the hull and near the center axis of the waterline. As fuel and water quantities increase and decrease there is no change in sailing trim on a Shannon. A good rule of thumb for comfortable, non-rationing, long ocean passages is a gallon of water per person a day for washing and eating. So four people on a 20 day trans-Atlantic passage will require at least 80 gallons of fresh water without water conservation. Another factor is the availability of fresh water. In many parts of the Caribbean, Pacific islands and Far East potable water can be difficult to obtain. All Shannons, regardless of length, have enough water tank capacity to enable two people to live aboard for two months without concern. Since capacity and redundancy are as critical as trim, Shannons have multiple water tanks each with its own shut off to allow water management. All water tanks in Shannons are custom 316L stainless steel and have a remote gauge plus the backup of an access plug for checking with a dipstick. Fuel capacity also must both sufficient range and provide for the contingency of only bad fuel being available. Shannons have over 500 miles of powering range at cruising speed with standard fuel tanks. The range can be considerably increased by a small reduction in speed. All Shannons have over-sized engines to compensate for heavy alternator loads, refrigeration compressors and horsepower overrating by engine manufactures. The fuel tanks are made of 5052 marine alloy since stainless steel reacts adversely to diesel fuel. The total fuel capacity can be divided into two or more tanks depending on the model. The fuel lines of all tanks go to a fuel manifold with individual isolator valves for both the pick up and return lines. Finally, in keeping with Shannon's philosophy of total access, the fuel tanks also can be removed without destructive consequences.
