Fuel Quantity for Blue Water Cruising

[JazzyO]

Originally Posted by svseachange

We need more solar, more hand steering and/or more diesel.

I was struggling with the plan for my boat, considering there is no room for solar on deck, windgens are ineffective a lot of the time, and the tankage onboard is small. And then it hit me: Watt&Sea hydrogenerator. My boat does 6kts fairly easily and then she delivers 300W. This way all my energy needs whilst underway are met and you arrive with full batteries at your destination.

If anyone wants to order one, be aware they are popular these days and the "factory" can't cope. Mine has been on order for over 2 months, no sign yet.


Onno

[StuM]

> My boat does 6kts fairly easily

Including when you are dragging a generator through the water?

[TeddyDiver]

Originally Posted by JazzyO

Doing the math, if you use all of it, you use 6.4 gallons per day. I cannot imagine using that much on a sailing vessel. But you must have good reason to take that much (I presume a large part of it is backup considering the region you sail in? Even so - it seems a lot.).


Onno

You right about the region. The sailing season is barely two months at the most and half of the time could be windless, so got to be prepared to a lot of motoring. That's up to 1200Nm depending where you are (plus reserve).

[Jeannius]

Talbot... We carried an extra 50 gallons in jerry cans. They all fitted in the cockpit lockers. Didn't need to use them on the Pacific crossing but was really glad we had them when we arrived in FP. The price of diesel ( and everything else ) was horrendous!

[zboss]

Originally Posted by StuM

> My boat does 6kts fairly easily

Including when you are dragging a generator through the water?

They produce so much power than even if they were to drop your speed from 6 knots to 5 knots, which is not likely, you would only have to charge for 2 or 3 hours, then lift the generator out of the water.

So over a 30 day voyage you are maybe only losing a day.

[Nicholson58]

Originally Posted by StuM

> My boat does 6kts fairly easily

Including when you are dragging a generator through the water?

I hear they make great lures for very large fish Lots of tales of nothing left but the cable at dawn.

[Nicholson58]

We are 36 tons, 58 feet X 16 beam. 115 6-cyl Westerbeke. We steam at 7 to 9 knots in fair conditions. 9 to 10 knots flat & windless. Fuel use is about 4 km/gallon. We have 5 diesel tanks totaling 370 gallons. We haul 6-gallon cans on deck. That allows manual fueling when the marina rate is obscene. Generator is 12 kw. I didn't choose this - came on the boat. We are adding 660 watts solar this spring. Fridge/freezer is AC so we currently run the generator about 3 hours every other day. I plan to add 24 VDC cold plates for solar refrigeration. We are on the Great Lakes for now so no water maker yet. There is a belt drive refrigeration compressor too but the belt drive is badly designed (PO). I need to make some complex brackets.

[StuM]

Originally Posted by zboss

They produce so much power than even if they were to drop your speed from 6 knots to 5 knots, which is not likely, you would only have to charge for 2 or 3 hours, then lift the generator out of the water.

So over a 30 day voyage you are maybe only losing a day.

Going a bit OT, but it's sort of relevant:

I've never researched W&S hydrogenerators before, but they sound promising, so I took a look at Cruising hydro generator

120w at 5knots. So less than 10 amps. And it looks like about 200w at JazzO's 6 knots or maybe 15 amps.

And they only work when you are underway on a passage - not at anchor.

They look like a good option under certain conditions, but they don't appear to be the answer for most cruisers.

[StuM]

Originally Posted by Nicholson58

I hear they make great lures for very large fish Lots of tales of nothing left but the cable at dawn.

The W&S isn't towed. It's looks like a little outboard motor.

[Nicholson58]

Certainly an option. It is a nice piece of equipment. I priced these things a year ago and was shocked. Here is the site but no prices.

Cruising hydro generator

[Talbot]

Originally Posted by Jeannius

Talbot... We carried an extra 50 gallons in jerry cans. They all fitted in the cockpit lockers.

My tankage is double the normal (two additional 90 ltr tanks in the forward lockers) hence the total. I dont have the locker space you do, but reckon 4 jerry cans diesel and one petrol (for the outboard) is possible.

What did you use as the lines for Panama - what size/length

[Talbot]

Originally Posted by StuM

I've never researched W&S hydrogenerators before, 120w at 5knots. So less than 10 amps. And it looks like about 200w at JazzO's 6 knots or maybe 15 amps.
And they only work when you are underway on a passage - not at anchor.

I would hope with 555 watts of new Yingli solar panels and an Outboard Flex 60 controller, I ought to be getting a lot more than that! Without drag or noise!

[Zanshin]

I approach this fuel question from a bit of a different angle. With modern weather forecasts becoming more accurate as well as the instant ability to get this weather aboard, one will have a good 3 days of warning of a really big storm, one that is sufficiently large to warrant getting out of the way. Since winds are usually bad for escaping large lows, one would want to be able to motor and/or motorsail for 3 days (72 hours) in order to get out of harm's way. The Pacific is big, so one might need to do this twice.

Thus I'd compute my fuel capacity to let me motor at cruising speeds for 144 hours, plus the amount of fuel I would need in order to supply electricity for onboard requirements.

[svseachange]

Originally Posted by Talbot

I do plan to spend a year in the mediterranean before moving to the west.

I think that is really the smartest thing you can do. You will answer this question and many others during that year. Maybe do not spend too much money fitting out your boat until you after you do this?

[uncledom]

I haven't fully researched these but they look interesting. Very low noise, makes power when motoring, sailing or when at anchor with a breeze. According to the promo they "present themselves as a pillar in high winds" so that they can't overspin. I've toying with the idea of having them on a frame on the stern rather than on the mast.

http://kronosenergysolutions.com/Win...ts/mastR1.html