With hundreds of long-range canyon trips under my transom since the mid-70s, I have learned a thing or two about tweaking maximum range out of my outboard-powered MarCeeJay charter boats. For Florida boaters, with the proximity of the neighboring Gulf Stream to many East Coast inlets, this is not as demanding a prerequisite. Venture to the distant Out Islands of The Bahamas or steam out to the oil rigs deep in the Gulf of Mexico and you’ll likely need auxiliary fuel to make it back home.
Before we discuss extending your fishing boat’s roaming capability, you must first establish an accurate benchmark for its existing range. A guideline that has served me well for the past five decades is what I call the 10-hour rule. Translated, your vessel should provide a minimum of 10-hours of running time at optimum cruising speed on its existing onboard fuel supply, plus an additional 10-percent for reserve. This rule is absolute dogma when heading 80-plus nautical miles offshore, trolling for 7-hours or more and then making a safe return trip back to port.
Knowing your vessel’s fuel burn at various cruising RPMs is mandatory to determine your boat’s range, as is the knowledge of how much fuel is in the tank.
Knowing your vessel’s fuel burn at various cruising RPMs is mandatory to determine your boat’s range, as is the knowledge of how much fuel is in the tank. To see if your platform passes the 10-hour test, take 90-percent of its stated fuel capacity and divide this by your vessel’s fuel burn in gallons per hour at optimum cruising speed. If your boat is set up properly for long-range fishing adventures, this number should be 11 or higher. So what are your options if your boat fails this safety range benchmark?
I am guilty as anyone with regards to having carried spare gas cans onboard when heading offshore. This is certainly the simplest and least expensive way of increasing your boat’s fuel capacity, but it’s also one of the most dangerous. There’s a reason many marinas forbid this practice. One of them is safety and another is to avoid the chance of spilling hazardous fuel into coastal waterways.
If you must refuel your boat with plastic jugs, I recommend performing this procedure as soon as you’ve burned enough fuel from your main tanks to hold the auxiliary. When it’s time to do the deed, I’ve had best results heading down sea at a slow idle. Unscrew the tank’s fuel cap, use an oversized funnel as an expanded target and primary catch basin and pour the contents quickly and accurately into the fill port. Close it up, and stow the empty tanks with vents open, tied securely in the bow (not in the cabin or in the bilge) and be on your way. Another method to transfer fuel from portable plastic jugs to your main fuel tank is through a siphon or hand pump, which minimizes the chance of spilling fuel in the water or on the deck.
When transferring fuel in the open ocean there’s no room for error. The safest and easiest way to extend your range is with the use of collapsible bladder tanks, which take up precious cockpit space when filled, but fold flat and compress nicely when empty. Fuel bladders are a neat and safe way to accomplish the task of lugging along extra fuel for a variety of craft, both outboard powered and inboards.
To learn more about the use of modern fuel bladders, I contacted Dave Dack from Aero Tec Laboratories. They started out in the fuel cell industry over 45 years ago manufacturing non-exploding, crashworthy fuel tanks for motor racing. Since, they have expanded their client list to include the U.S. Military, commercial construction and marine interests, plus recreational boaters. ATL currently offers two different styles of auxiliary fuel cells, a Petro-Flex pillow style marine fuel cell and a FueLocker space-saving fuel bladder. The difference is that the pillow bladder lies flat on the deck with a lower overall height and takes up more cockpit space. Conversely, the FueLocker has a smaller overall deck footprint, but has a higher vertical profile. The pillow style bladders range in size from 25-to 500-gallons, with the FueLockers ranging from 50-to 500-gallons. Both are manufactured from a milspec nylon reinforced synthetic rubber material and include a rubber under liner. Options include fuel system connection hardware, tie-down kit, storage bags and more.
Fuel bladders are used primarily as secondary fuel sources, rather than being connected directly to the engines, which can be a nightmare scenario if one of the tanks pops free and starts squirting fuel in the cockpit and into the bilge. If you have extra room, installing an auxiliary aluminum tank is a more permanent solution to your boat’s fishing range shortcomings and probably the best option for the long term. If you have to cut up your cockpit to get down below, skip the hassle and stick with the bladder tanks. Whatever method you prefer, use extreme caution and in case of emergency it’s imperative your safety equipment and fire extinguishers are easily accessible.