A confession....

[Baker]

My boat is relatively new to me. I have not explored the "lower regions" of the fuel gauges. On my Carver, I think they tried to idiot proof the gauges as they still had a significant amount of fuel when buried on "E". I found it that on my new to me Meridian, that is not the case!!! When they are on "E"....the damn thing is EMPTY!!! The boat carries 400 gallons in 2 tanks.

We had a Lake Charles trip. Luckily a week before the hurricane. I left my home port of League City, Tx with fuel spilling out of the vents...figuratively speaking. We made it to Lake Charles with just a needle width below half a tank. Now I am smart enough to know I am not gonna make it back without adding fuel.

On our way back, we were to stop on the Beaumont area to visit Wendy's sister. I had plenty to make that so off we went. We had our visit for a day or two and then went on our way. THere is a fuel stop at the Sabine Pass Port Authority. I stopped to put fuel on. I did not put a lot on as I wanted to run "light" and also the fuel there was a bit pricey. I had a smidge over 3/8 of a tank....which should be a smidge over 150 gallons with 85 nautical miles to go. My boat gets at least .75mpg at 20 knots.

Well off we went and out the jetties into the Gulf we go. It was a beautiful day and calm conditions. My only concern was how rapidly the fuel was disappearing on the gauges. There was no doubt we could make Galveston where fuel was available. No doubt whatsoever. So I would reasses once we enterted the jetties there. We did that and I still had just a smidge below 1/4 of a tank with about 30nm to go. So the next checkpoint was a place called Topwater Grill....which is our favorite restaurant on the water AND they sell fuel. We passed there with just a smidge below 1/8 of a tank with about 15nm to go. So I made the decision to continue. We made it just fine into our home slip.

Fast forward to the next weekend when we have daughter home and a friend of hers. She wants to go for a boat ride. Well I know we need fuel. So we fire up. The left engine started a little "weirdly" but it came up on line. The fuel dock is literally a 50 yards from my slip as the crow flies but I have to go out and around our pier....so let's say 200 yards travel distance. About 50 yards from the fuel dock the left engine quit.....out of fuel!!!!!! Of course I was in denial and feared something bad was wrong....but the minute I opened up the Racor cannister and saw tumbleweeds in there, I had to come to grips with the truth. Filled up. Pumped the lift pump. Engine started....and died. RInse and repeat a few times and engine up and running fine! Have since run the boat and runs just as great as ever. The right tank took 191 gallons(out of 200). I was unable to top off the left tank as a lightning storm moved in while trying. I was awfully curious. But I still managed to get 183 gallons in before they cut me off.

Well I guess I know my gauges a little better now. The gauges indicate more "optimistically" while up and running on plane. The sender must be in the rear of the tank. The first half of the gauge/tank seems to burn slower than that last half. And by golly, when it says "E" it is EMPTY!!! There is actually a double index at "E" on the gauge. I did not go beyond that first index. I figured I was safe by nor penetrating that little gap between the indices...but guess not. Anyway, it could've been worse I guess. And I will no longer run the boat much below 1/4 of a tank from here on out...

 

[fgarriso]

Do you not have sight tubes on your fuel tanks?

 

[rsn48]

I have two new tanks and two new fuel gauges, so I'm going to be on alert for the first while as I get a feel for "reality."

I have two 80 gallon tanks and I put 10 gallons in one and nothing showed up on my fuel gauge.

 

[rslifkin]

As far as I know, mine also mean empty when they say it. Never run them down that far, but based on estimated fuel vs actual fuel pumped, they're pretty linear. Tanks are a little bigger at the top, but not much and it's possible the gauges account for it.

As far as reading on plane, mine also read a little high. And a little low at low speed, especially when the tanks are lower and we're higher in the stern. The actual level is somewhere in between the planing and stopped/slow readings. Fortunately, it doesn't take more than the first couple of fills to figure out how to estimate it pretty accurately.

 

[OldDan1943]

LOL, folks you gotta learn, remote reading tank gauges are a 'suggestion.'
Sight glasses are much better until you get to the lower sight glass valve.
And of course that is when the boat is level and the fuel supply is at the bottom of the tank.

 

[rslifkin]

LOL, folks you gotta learn, remote reading tank gauges are a 'suggestion.'
Sight glasses are much better until you get to the lower sight glass valve.
And of course that is when the boat is level and the fuel supply is at the bottom of the tank.

That's why I always estimate gallons needed before filling and compare to actual gallons. That way every fill-up calibrates my interpretation of the gauges. No sight gauges on my tanks and they wouldn't be easy to stick either. So working gauges and knowing what they're telling me matters.

 

[GFC]

OK, for your pennance say 10 "Hail Neptunes" and donate to Sailors Society.org and your confession will be heard and you will be pardoned.

 

[Comodave]

I never run mine that low. I don’t think we have ever gone below 1/4 of a tank. I guess that I may be a bit paranoid about running out of fuel so when I put in fuel I always top it off.

 

[koliver]

A colleague new to boating had a "new" boat, moored at Point Roberts. I was entering Active Pass when I heard a voice I recognized, telling the CG he was adrift in Active Pass. As an active member of the CGA as it was known then, I took the call, found him and got him into a dock from which he could get gas easily.
For years, our common colleagues referred to me as the guy who had "saved Richard's life".
He had put some fuel in before the trip, but knowing his gauges would have saved him the embarrassment and danger of being adrift in Active Pass.

 

[Lou_tribal]

I never go below 1/4 on the gauges, just in case, and I do not want to find out if E really means Empty !

L

 

[menzies]

I have three tanks. Two 425 saddle tanks and a 150 forward tank.

When going on our extended cruise we fill the forward tank and lock it down. Nursed it will take us 250 miles with reserve. Enough to get us somewhere to correct an issue.

That is our insurance should something happen to the other fuel - like taking on bad fuel in the islands.

If we are running low when about to cross back we still put enough in before we start rather than using the forward tank. Once back in the AICW we then use it.

 

[jleonard]

That's why I always estimate gallons needed before filling and compare to actual gallons. That way every fill-up calibrates my interpretation of the gauges. No sight gauges on my tanks and they wouldn't be easy to stick either. So working gauges and knowing what they're telling me matters.

I always did the same thing and was able to get very close. That's a gage on one tank only with an equilizing line between the two "saddlebag" tanks.
Close enough so I never bothered to look at the sight tubes.

 

[O C Diver]

My boat is relatively new to me. I have not explored the "lower regions" of the fuel gauges. On my Carver, I think they tried to idiot proof the gauges as they still had a significant amount of fuel when buried on "E". I found it that on my new to me Meridian, that is not the case!!! When they are on "E"....the damn thing is EMPTY!!! The boat carries 400 gallons in 2 tanks.

I have one very simple question.
Considering what you do for a living, who decides how much fuel goes in the airplane?

Ted

 

[tiltrider1]

I must be really paranoid. I know exactly how much fuel I have. I burn 10 gallons an hour and I start with 650 gallons. I periodically confirm my calculations with a look at my sight tubes. Bottom of my sight tubes means I have 8 hrs til engine shut down and 4hrs is the deepest I have ever been willing to go. I have run all tanks dry on tests, never all at the same time, to determine total usable fuel.

 

[FlyWright]

I never go below 1/4 on the gauges, just in case, and I do not want to find out if E really means Empty !

L

Have you ever filled up from 1/4 to see what "1/4" really means?

After cleaning and servicing my tanks years ago, I installed a sight tube and calibrated the gages as I filled her up. My gages are terribly inaccurate but my Sharpie pen marks clearly denote 1/2 and 1/4 on the gage glass. My sight tube (Stbd side only so far) provides a physical verification of fuel remaining.

I never checked the gage accuracy at rest vs at cruise but my deck angle doesn't change much like those of you with 'fast trawlers'.

Great reminder, John. Thanks!!

 

[Sailor of Fortune]

If thats the worst thing to happen to you this week, your good!

 

[rslifkin]

As a note on learning gauge accuracy, we topped off the tanks this afternoon. I figured based on the gauges that we were just about half or a hair over. So I figured 10/ gallons a side or a little more. Exactly half would be 210 total. Total fill was 208 and change, so pretty darn close.

Last fill-up before that my guess was 230 total, we took just under 231. Usually I'm not quite so close, but within 10 gallons or so isn't uncommon.

 

[Spinner]

I second the recommendation for not running off the bottom 1/4 of the tank. In addition, I would never rely on a float-type gauge because they are notoriously inaccurate. On my Nordic 42, I have 3 sources of info on the fuel in my tanks:

Meratron tank gauges, tank sight tubes, and Meratron fuel flow sensors. Actually there are four. The last method is a tank tender system, which I don’t use as it’s kind of imprecise. The most useful of these is the fuel flow system because it provides real time info on my fuel burn rates.

 

[Lou_tribal]

Have you ever filled up from 1/4 to see what "1/4" really means?

After cleaning and servicing my tanks years ago, I installed a sight tube and calibrated the gages as I filled her up. My gages are terribly inaccurate but my Sharpie pen marks clearly denote 1/2 and 1/4 on the gage glass. My sight tube (Stbd side only so far) provides a physical verification of fuel remaining.

I never checked the gage accuracy at rest vs at cruise but my deck angle doesn't change much like those of you with 'fast trawlers'.

Great reminder, John. Thanks!!

I did, and know that my gauges are quite accurate to +- 20L (each of my tanks are 250L). However I also know (now) that I should never top up tanks (fuel return). When at around 1/4 on the gauge if I take 150L to 160L on each tank I am fine for a good while.

L

 

[Baker]

If thats the worst thing to happen to you this week, your good!

You get it Steve!!!!

 

[rgano]

Thankful for having new WEMA float sensors in fwd ends of both tanks and a means to read either on the console; calibrated sight gauge between the tanks enabling me to read either; selectable return so I can top up and not worry about return fuel ending up in the water; BOTTOM draws at the aft ends of the tanks; and lastly a Floscan totalizer reset at each fill. Makes it hard for me to screw up. Gambling on the 200 yard trip, I'll give you a pass. On the other, not so much.

 

[AlaskaProf]

Baker. I note: "Jetsome". Is it possible you are actually a pilot? Did you miss the lesson where we were taught to manage fuel with the clock, not the gauges?

Get a small notebook, burn a quarter or half on your unreliable gauges, noting start and stop times faithfully. Fill and calculate actual burn. Then ignore gauges.

See also United 173, 12/28/1978.

 

[kapnd]

Baker. I note: "Jetsome". Is it possible you are actually a pilot? Did you miss the lesson where we were taught to manage fuel with the clock, not the gauges?

Get a small notebook, burn a quarter or half on your unreliable gauges, noting start and stop times faithfully. Fill and calculate actual burn. Then ignore gauges.

See also United 173, 12/28/1978.

Never trust your gauges!
After a few fill ups, you can get a pretty good idea what your consumption is going to be.
I keep a grease pencil on the dash and keep a tally on the corner of the windshield of estimated daily burn to compare with the gauges.
Many years ago my Dad informed me that it didn’t cost any more to keep the top half of the tank full than the bottom half!
(This tidbit was delivered to me in the middle of the night when Dad would have much rather been sleeping than out saving my stupid ass!)

 

[FoxtrotCharlie]

We hold 300 gal per side (two tanks each side). The site tubes go from top to bottom exactly 30 inches - tanks are linked - one site tube per side. I took apart two cheap tape measures and cut the tapes off at 30", glued them directly behind the tubes - one inch equals 10 gal. The tanks are rectangular. Very easy to determine whats left

 

[psneeld]

Time works...except when it doesn't and the average fuel gauge is the biggest liar on the boat beside the captain.


If you don't have sight tubes or can stab a fuel tank... you might have to come up with a system of cross referencing fuel gauges calibrated by time and progressive filling and watch both regularly.

 

[hughespat57]

I drained my tanks during a repair and then refilled 10 gallons at a time in each tank.
Recording in a "fuel chart" exactly where each 10 gallon mark was for each gauge.
i.e.
10 needle width below 1/8
20 bottom edge 1/4
30 between 1/4-3/8
40 just above 3/8
50 on 1/2 etc.

My rule for operation 1/3 reserve,
2/3 for travel point to point (or 1/3 out and turn around 1/3 back)

 

[Wayfarer]

I feel your pain Mr. Baker. I learned this the hard way with my last boat. My gauges said I had 1/3 of a tank left, but it was more like 0/3. I had to get towed the last 200 yards to the fuel dock by a friendly local on a jet ski.

Oops.

 

[KnotYet]

I feel your pain Mr. Baker. I learned this the hard way with my last boat. My gauges said I had 1/3 of a tank left, but it was more like 0/3. I had to get towed the last 200 yards to the fuel dock by a friendly local on a jet ski.

Oops.

I love the 'happy' ending, though!

 

[jimdavi]

We hold 300 gal per side (two tanks each side). The site tubes go from top to bottom exactly 30 inches - tanks are linked - one site tube per side. I took apart two cheap tape measures and cut the tapes off at 30", glued them directly behind the tubes - one inch equals 10 gal. The tanks are rectangular. Very easy to determine whats left

Our NP 45 came with glass sight gages On each 200gal tank. 1 centimeter equals 4 gallons. Interestingly, measuring usage from the smart craft gallons used is exact with the mechanical measurement. Pretty cool!

 

[FF]

"and lastly a Floscan totalizer reset at each fill."

Its more accurate to log the Floscan readings and wait for 2 or 3 refills.

Then reset the Flowscan.

You can get to predict almost to the gallon the fill.

For folks that want a simple fuel gauge the Tank Tender is probably the easiest refit