Fuel and Water requirements for passage

if you fit a watermaker, fit an electric one, here are my thoughts on it, if the engine does fail for any reason you can still make water because of the solar power, yes it will be limited, but it will keep you going until you can ressurect the engine, the other problem is heat watermakers do like to be kept cool, yes we all tuck them under bunks etc, but do we give it any ventilation?, remember these are high pressure pumps and all pumps get hot, most of the boats i have seen have a small spigot into the sink and when the watermaker is first fired up everyone i ave talked to seems to allow half a gallon or so go over the side, and then they sample a glass, if its alright then the tap is turned off and its redirected to the tank....this is what i have gleaned from all the cruisers i have met, as another point what pilot are you going to use to drive the boat?........keith

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Thanks for the advice.

The autopilot was selected after a great deal of research, My Cat has always had an Autohelm 3000, which is limited, but ok for the overnight type trips. I have been advised time and again by multihull owners not to use a windvane type pilot (electric or manual) due to the problems associated with the far faster acceleration that such a boat has over a monohull. I have purchased the new S1 system from Raymarine (replaces the ST6000) with the idea that if necessary I can upgrade to a S1G later. This not only gives me a robust auxiliary steering, but also provides a secondary steering system if the link between wheel and rudder quadrant fails.

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we came across with a 3000 and it was a bit slow on the course corrections, gave us a few heart stoppers when we dug a bow in and surfed across the face of a large swell that was running, the acceleration was terrific and the pilot was nearly on full opposite lock before she came back, overweight boat, under powered pilot, we also found it hard to balance the boat (sailwise), we used a cruising chute but the sudden acceleration kept collapsing it....cest la vie........keith

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We have similar problems on occasion. Got a Snowgoose with a ST7000. Down wind in a 7/8 we surf a lot. We have broached a few times in gusts as the auto pilot cant react fast enough if we are not on the highest setting. On the high setting we use a hell of a lot of power and the motor gets very hot.

I have been told by Ray Marine that to cure the problem we need the gyro unit. This , I am told would reduce current draw on the motor and steer a better course.
It is £500 for the gyro so think I will just put up with the problem

The broaching didnt cause as much as a problem as I first thought. Pretty nerve racking but once side on to the wind, the sails are depowered, as they were set for running. Might be different if the waves were breaking!

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You may have been lucky, an unexpected broaching when on a run is very often caused by a breaking wave, with the rudder losing grip. And if you are poled out goosewinged or twin headsail, broaching doesn't release the pressure on the sails. I've been over to past 90 deg even in a F5-6 this way.

I've found a wind vane responds quicker and copes far better than an autopilot in strong winds.

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In my case it was caused by rapid acceleration down the face of a wave. We hit 16 knots and the boat rose out of the water about a foot as she planed. We didnt lose rudder grip but we did make a pretty rapid turn as we got to the bottom of the wave. Being a cat we didn lean over. All the advice I have had suggests that in these circumstances we wouldnt have been any better of with a wind vane. Prior to surfing we were doing about 8 knots.
The reality is that we should have been reefed down more. We were over powered but it made for some exciting sailing!!

When we are surfing at 12 to 14 knots the rudders are twitching all over the place as the autopilot, on its highest setting for response, attempts to keep us running straight. Under these circumstances everything feels good. Once we surf above these speeds we are over pressed and it all starts to go wrong

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I have found that problem too with the 3000. When the conditions deteriorate, (i.e. when you want the autopilot the most) the 3000 just can't hack it. I was going to upgrade to the 4000, but quickly found out that it suffers really from the same problem. The new S1 system has an upgraded drive from the old ST5000 and takes a lot of power (50 amphrs/day approx) but you gets what you pay for! The other problem that I have is that the drive needs to be in a dry compartment, and the quadrant on the Catalac is definitely wet. I will be adding sugar scoops to provide that dry compartment, and this will also give me additional waterline length. With the bulbous bows that I am fitting, this will give me the best part of 2m additional waterline! I think that might make a difference to the handling!

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water allowance was 1 gall/person/day for HM Navy. That included none for personal washing but did include for soaking salt meat.

I've found 5 litres/person/day adequate including the odd freshwater wash.

On diesel it's a little more variable - if you've a smart regulator and a big (100+ amp) alternator 60 mins/day should keep your batteries charged. That discounts any solar or wind generation you might have. I've found 185 watts nominal from those 2 sources delayed by 2 days the need to recharge.

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Re: Surfin\'

I fully intend having both drogue and parachute anchor as part of my heavy weather kit and a catalac will plane really nicely given the right stimulus (and I do mean plane not surf)

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Must be a very personal thing, our boat's ( Halcyon 27 ) did two Atlantic crossing using no water tank, and 15 x 5 litre plastic containers for two people. For battery charging they used a alternator ( running on the flywheel of the Sabb 8 hp )controlled by a wire to a resistor that allowed output voltage to be adjusted. There was a hydrometer and chart for checking state of batteries, together with Watt meter, Ampmeter and Voltmeter, with a wind generater as well. Must be the bargin basment set-up, but it got them there and back via West Indies and the Med.

One interesting mods was the fitting of two 4 inch dia cockpit drains straight out of the transom when they reached the States.


Brian

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Re: watermakers

various boats on the arc had watermakers fitted in the canaries. most subsequently swore at, not by, them.

if you get a good reliable one it will certainly save you some hassle and make mid-ocean showers possible but unless you plan to go well off the beaten track it's an expensive luxury.

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Re: watermakers

expensive luxury across the atlantic, rather more important for the pacific - which is where I will be heading.

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I tend to agree

mainly on the cost-benefit analysis so haven't fitted one.
My calculation for oceanic passages is that you're as well off using the main and boom-bag to catch rainwater.

Mind you only 1 of the people to whom I spoke found their watermaker OK in the Med - that was Francois Gavot, but then he's into longhaul Airbuses and was a flight mech, so tends to be into anything "technically difficult".

His is actually made on the Cote d'Azur, unlike the rest which seem to be US W coast.

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Re: Surfin\'

I've done a couple of long runs (150M+) in continual surfing conditions in a 31' monohull using an Autohelm 4000 ST, with no problems except excessive damp and nausea.

Mind you it's acknowledged that multihulls are inclined to be less seaworthy;-)

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Re: Surfin\'

I think the final statement comes under the heading of trolling /forums/images/icons/smile.gif When it comes to downwind sailing I would rather be in any multihull than a mono, that deep cyclic rolling from side to side must really get up your nose!

I would be quite happy to go 200 miles on my old 3000. But continuous use over 30 days requires a rather more robust designed machine IMHO

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I would be interested to see a picture of your boat when you have scooped it, i intend to do somethingvery similar, but more aimed at the boat under engine as she squats really badly, and adding three feet to the back end could only improve matters, bulbous bows? thought about it, and the main benefit would appear that it reduces the pitching that cats of our genre were susceptible to ( catalac oceanic heavenly twin) because of the pronounced rocker in the hulls, personally i think your heading in the right direction, i know people will disagree with some of what i say, but thats what forums are all about..a free exchange of ideas and experiences,........see you when you get this side.......keith

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