Article by Capt. Mark Sampson
Why is gas at marinas so expensive? And why doesn’t everyone just buy it on the road where it’s a lot cheaper? Actually a lot of people do, in fact, every morning during the boating season it’s common to see anglers with their boats in tow making one last pit-stop on their way to the public ramp to fill their boat up at one of the West OC service stations with gas that’s sure to be “cheaper” than what they would pay for it at one of our local marinas. Smart move right? Well - not necessarily so…
One reason marina gas is so much more expensive than what you buy on the road is that it’s missing something. Which, of course, doesn’t make sense - if it’s missing something you’d think it should be “cheaper” - but that's not the way it works. What you don’t get when you buy gas at most marinas is a dose of “ethanol” in your tank.
For a long time now the pumps we use at service stations have been sporting stickers reminding us that “this gas contains up to 10% ethanol”. Ethanol is basically alcohol made from corn, and while people might argue one way or the other about whether blending ethanol with gasoline is a wise plan for accomplishing the goal of reducing our country’s use of oil, helping the farmers out, or keeping the air cleaner, no one should disagree that the darn stuff isn’t doing us boaters any favors.
Years ago I had the “privilege” of paying close to a thousand dollars to have one of my outboard motors repaired. That hurt…it really hurt! Like every other boat owner, I’m accustomed to paying what sometimes ends up being big bucks for maintenance and repair of my vessels. But engine repairs usually entail replacing parts that have worn out from frequent or extended use, and even though the engine was at that time no “spring chicken”, there were not enough hours on it that should have required that kind of service. So what was the malfunction? One word “ethanol!”
Back when non-ethanol gas was not only more expensive, but also hard to find on Delmarva, I didn’t use it in my boats. Instead I bought regular (ethanol) gas at the service stations and used fuel additives that advertised they would stave off the negative effects of the alcohol based fuel. But despite their claims - they didn't work. And as I learned more about the fuel, I came to understand that additives alone aren’t enough protection for a boat engine because no matter what you do “time” will still take its toll on this fuel and create problems unless it’s used within about 90-days of purchase.
These days marine engines, fuel lines, tanks, primer bulbs and such are designed to handle ethanol fuels, but the older stuff isn’t. But even if a vessel’s entire fuel system is designed to handle ethanol, problems can still arise from the miserable characteristic of the fuel to absorb water. Unlike our automobiles which are usually driven enough that the fuel in the tank is always relatively fresh, the fuel in boats often sits for weeks if not months without being used, allowing plenty of time for enough water to be absorbed from the air to sometimes overwhelm a fuel filter that it stops the flow of fuel to the engine. In some cases the water will get past the filter and into the engine. Either way, the water in the fuel puts an end to the use of the motor until it can all be cleaned out.
Back when I was still using ethanol gas I took a little boat of mine out for a quick test run. The 25-hp motor hadn’t been run for a while and I was happy that it started up right away and ran like a champ. Until, that is, I was almost home from my voyage and the engine suddenly sputtered and shut off. After paddling about ¼-mile home it was easy to locate the source of the problem. In the course of 3-weeks the 6-gallon fuel tank, which only had a couple gallons in it since it was last used, had absorbed about a pint of water, much of which ended up being sucked into the engine. I was reminded how poorly an internal combustion engine runs on water.
Another potential problem can arise from the fact that apparently ethanol works somewhat as a detergent that will help to break down and clean the residues that sometimes build up in gas tanks and fuel systems. While that might seem like a good thing it can also lead to trouble as those deposits don’t just go away they float around in the fuel and eventually find their way into the engine which can gunk things up. Naturally, with a spanky new vessel that has always run on ethanol fuel this will not likely be a problem like it might be with an older boat.
I admit to being the biggest penny-pincher in town and always ready to take full advantage of every opportunity to save a dime anytime I can. But when buying gas, whether for my lawn mower, weed whacker, generator, roto-tiller, and boats, or anything except my truck, this tight-wad is willing to pay the extra price to ensure that the gas keeps it running - not the opposite.
So anyone who has a power boat should have a “fuel” discussion with whoever does their engine service and ask about what kind of fuel they should be using and what additives (if any) are recommended to be used, and then still be ready for potential problems if they chose to use fill their boat up at the convenience store. §
