Mileage

[Bob G]

Ineed to move my boat about thirty-five miles, probably against wind and wave (10-15 KNOTS AND 1-3 FT). Although I am trying to wait for more favorable conditions, I may get in a time bind--
if so, it may take a lot of motoring. After 2 1/2 years I have have just gotten through my 10 hour break-in period on the 2 cycle evinrude 9.9 horse engine. Any one know about how far or how long an Ariel might go on a six gallon tank, or say, per gallon?
Thanks!

[Ed Ekers]

Over the years we have taken Pathfinder up and down the Central coast of California a number of times. We will often motor for very long period of times. With a 2 cycle 6 hp we would be able to make appx 30 - 35 miles on one tank of gas. This would be with the wind on the nose (10 - 20 knts) and in some very choppy sea conditions. As an additional point of reference I would carry to six gallon fuel tanks for a trip from Santa Cruz to San Francisco(72 miles). A couple of techniques we would use on these trips was always raise the main to help stabilize the boat, and never tried to fill the gas tank in the motor well so to avoid a flash fire. (that's why two tanks, just switched the hose)

[tcoolidge]

I have a Johnson 2 cycle6 hp outboard and can cover 30-35 miles on a six gallon tank of fuel easily but have only done so in calm flat conditions. If there is wind I sail even if, as is usually the case, it's right on the nose. It's a SAIL boat after all. The conditions you are describing sound like a wonderful sail to me.

[Ed Ekers]

Your right, it is a great sail. When heading north from Santa Cruz to SF I will often make it a two day trip. There is a little costal harbor about half way up the coast located a Pillar Point. The conditions there can get somewhat extreme in the afternoon, 30 - 35 knots with breaking seas and 6 - 10 ground swells. Throw in fog with less than 1/4 mile visibility and you all alone in your little battle ship. NO matter how much fun you try to tell yourself you having, cold wet and tired is just hard to overcome.

Before we got the GPS thing I used to have to slow down and look for the crab pot floats so I was sure I was at the line heading into the channel entrance. ( wasn't youth and carefree a wonderful thing). Now I will head out from Santa Cruz at 0dark early and try to get to the half way point before the wind builds.

The second day is still a thrill for me no matter how many times I do it. Sailing up the coast from Half Moon Bay and the making that right hand turn to go under the Golden Gate Bridge always brings a sense of joy and relief. Joy that I am back in the SF Bay and relief that I made the trip with that little Ariel one more time. And every trip has stories and memories that will last with me forever. I am sure you can relate.....ed

[Bill]

(This is being posted for Peter Theis who can't seem to logon :p )

My motor is a new 8hp 2 cycle Yamaha with a power prop. Older motors, or motors with a standard prop will probably not do as well on mileage. When the motor is going full speed, and the motor well cover open, I get seven hours of usage on a six gallon tank. My rate of travel is about 6.2mph, measured with a GPS. The reason I refer to the motor well cover being open is that outboards have exhaust pressure relief holes at the back of the motor, just under the engine housing. These breathe a little exhaust. If that exhaust remains in the engine compartment, it will reenter through the air intake in the front of the engine, and slow the motor down, as well as
increase fuel consumption. This is a problem with outboards, and I am looking for a good solution (and may have one).

If I run the motor in the 1/2 to 2/3 speed range, it seems I get about 12 hours on a tank, and my speed is reduced to about 5 mph. At near idle speed, a tank of gas goes forever, at about 2.5 mph.

Relating this to distance is a difficult matter. The reason I have to use full speed is generally a) to beat a storm, b) I'm tired or bored and want to get to my destination, or c) because the waves/wind (WW) are on the nose, and are knocking me. It takes very little in the way of WW to slow progress down to 5+mph (at full motor speed). When the boat goes to the lower 4+ mph, the motor is having difficulty going forward. When in the 3 mph range (still at full motor speed), I am concerned about not having enough power. In the 2+ range, there are times when my forward progress can stop, and steerage can become a problem and concern (this is all at full motor speed). Often it is necessary to tack the boat, under motor power only, to make forward progress. This means that the velocity made good (VMG) is less than what the forward hull speed.

The reason this information the effect of wind and waves is significant is that (and I have had this experience) if you leave a port with 25 miles to travel under motor power, and there is no wind, you will arrive at your destination having only used a little over a half tank of gas and a long morning. If there are wind and waves, on the nose, it could be a very long day (if you make it) and require two six gallon cans of fuel. On a calm day, I have traveled 60 miles on a 6 gal. tank of gas. So, in summary, distance is not the controlling factor. The wind and waves are.

However, there is a way around this problem. On one of the last legs of my journey this summer, I had only 25 miles to travel port to port. with only 6 miles to go, I was rapidly approaching the bottom half of my last tank of gas, with night time approaching. My forward speed, motor tacking, was in the 2-3 mph range, and often going to 0 mph. In desperation, I raised a reefed main, and motor sailed the boat into port, pushing forward through the wind and waves at 5+ mph, and with the motor at less than full power. Using the sail and motor combination I was able to point significantly higher than if I were using sail alone, and oft times the sail would show a slight luff. However, there was no doubt that my velocity made good was a multiple of the VMG before raising the sail, and the ride through the waves was an order of magnitude easier.

In summary, when faced with oncoming wind and waves, raise the mainsail in addition to motoring and you'll get there faster, easier and with much less fuel consumption.

[Bob G]

Thanks for all the mileage help, everyone! The trip is done and I still don't know how far she'll go on a tank, or even a gallon. Had a good wind, let my 12 year old son play hooky from school and made the trip averaging almost 5 kts pointing pretty close the whole way. Never tacked once (twenty some miles) until our course reqired a turn directly into the wind. I carried about 12 gallons of gas and probably didn't use a gallon. Best sail of the
2001 season for us. That it-- she'll be hauled out for the Lake Erie winter in a couple of days. Thanks again!