Boat pulling to port and other noob questions

[Hermit Scott]

I just motored my Catalina 30 for the first time. That is the first time I was ever even on a sailboat on the water, I have a few questions for you guys as I don't have any people in person I can ask, not that they would know more than you, just that they could look at it in person.
1 The boat has a Yanmar 12 HP engine, is 5 miles an hour a good speed pushing a 10,000 lb. boat?

2 A somewhat related question to the first is how would I know if the clutch mechanism was slipping? That is the one thing in the engine I didn't replace.

3 The boat would pull to portside when I let go of the wheel. The wheel would actually turn to the left when I let go, I looked at the mechanism for the steering and it all looks good and symetrical. I scraped 5 years of growth off the bottom a month ago but it wasn't perfect b/c I ran out of air and only had one tank with me. Could that cause it? There is nothing on the boat so I am not sure if weight displacement could have been a factor, but I had a battery in front of the engine compartment instead of in the starboard compartment, could that have been enough to pull the boat to portside? Wind wasn't a factor, it pulled no matter which way the wind was coming.

4 I have a marine airconditioner that works well with shore power. I want to buy or build a generator that will run it. I don't know any of the specs on the A/C. What would be a safe sized genny to be sure I can run the A/C while on the hook? There are no DC motors in the A/C. I am sure they are all alternating current motors. I understand there is a large start up drain in power for the alternatingcurrent motors. Does the genny have to be large enough for the start up loads or will the batteries compensate for them? Basically what I am asking is what size generators do you guys that run air conditioners on the hook use? My wife may actually accompany me if I can provide airconditioning.

 

[Anchor Down]

Hey, Scott,

I'm a fellow C30 owner, and I can answer your first question with confidence.

Your prop is positioned directly afore your rudder: all the propulsive water flow travels right past your rudder. This is good for gaining steerage at very low speeds, but it also pushes against the rudder as it flies past, and makes you have to grip the wheel to counteract a pronounced pull to port. Once the prop stops, that pressure is gone, and it tracks straight and true.

You can test my response by getting to cruising speed under power, then closing down the throttle to idle. The pressure on the wheel should disappear immediately even before you decelerate under 5kts, then 4.5, 4, 3.5, etc.
Of course, when under sail only, there is no interference from the prop on the rudder, so you can give your forearms a rest until the wind picks up.

Sure, you want to get the rest of the bottom clean as soon as you can, though. You will never reach your speed potential (even after you learn all you can about sail trim) with a crusty/grassy/slimy bottom.

You stated you had a speed of 5 mph. Are you sure you weren't reading an instrument that gives speed in knots instead of miles-per-hour? If so, your 5 kt reading is 5.7 mph, only one knot under the actual theoretical hull speed for the C30: I'd be content with that. Any more throttle will just cause the engine to smoke and the stern to squat down in the water as the boat tries to climb up over its own bow wave, which it cannot do (this is especially true if the bottom is not clean). It's an exercise in fuel-burning futility. You'll gain another half knot, but at a big fuel price. It's considered bad practice, like forgetting to pull your fenders in and sailing around with them hanging over the side.

Under sail, a C30 will sail at her hull speed (around 6.7 kts) if the breeze is stiff, the bottom clean, and the sails trimmed correctly, and on the right point of sail (with the wind coming over the beam, or side, of the boat). All those conditions don't always converge, though, and most days, I'm happy with 5 to 5.5 kts in lighter air or if my hull is fuzzy.

I'll leave the engine and a/c questions for someone more knowledgeable than I.


Jeff

 

[sailaway78]

Prop Walk

Your boat pulling to port when you let go of the wheel while motoring is normal. Just a result of the prop torque. Unless it is extreme, then there is something else wrong. As for a generator, you will have to find out the wattage of your AC unit. Many seem to get by just fine with a 2000 watt Honda, but not all. Find out how much is necessary for the AC unit, then buy accordingly.

 

[RAD]

Scott

If you still have crap on the bottom that will slow the boat down and 5 knots with a 12 hp is pretty good but with a current it might be a little slower, as for a generator the Honda EU2000 is a small portable gas engine thats quiet and powerful enough to operate your AC

 

[Anchor Down]

Re: Scott

Scott,

For the a/c, you'll have to know what the start-up draw of the unit is, and then size the generator to exceed that number. The Honda E2000 is a spiffy unit, but it cannot put out more than its rating.

If it's close, you might be able to cheat the start-up a bit by turning on the fan full force, then engaging the compressor, to spread the peak draw out. But know the numbers before you buy.

A DC-to-AC inverter will allow you to run AC equipment from your batteries, but is normally used for things like power tools, coffee pots and other short-time draws. I don't know of anyone who is using his batteries to help start the a/c. Sizing the generator 15%–20% above the a/c start-up draw is the answer.
Jeff

 

[Hermit Scott]

thanks

I was using a GPS and the speed was in MPH but it isn't accurate enough to give a decimal, it could have been 5.9 or 5.1 mph. I haven't hooked up my batteries yet so I don't have a knot meter or depth gage yet.
If 5 mph is good with a 12 hp than I am pretty confident that the clutch isn't slipping, that's good.
It is a relief to know that the prop is causing the pulling. The bottom is pretty clean but not perfect. I wouldn't think it would be enough to cause that much pull.
I am glad to hear the estimate of 2000 watts of generator power to run a normal marine AC unit. I just wanted to make sure I was in the ball park of estimated power consumption.
I need to put an ampmeter on the shore cable and see what the AC is pulling to be sure though.
Thanks for the first hand about the C30. My sails are good but all the running rigging was removed from the boat before I bought it, and the roller furler is seized, so as soon as I get all that I will get to sail her. Then I will have a lot of other noob questions for you.

 

[Benny]

Gps gives you speed over land. If you are doing

5 knots with a 1 knot current you are only doing 4 over water. On the other hand if you are doing 5 against the current then you are doing 6. When testing for speed check your wind speed and direction and your tide table.

Clean the hull as any growth on it may amplify handling characteristics.

A Honda 2000eu puts out about 16 amps which is enough to run the compressor of most marine A/C units but the number of amps needed to start the compressor maybe 2-5 times the running requirement. A hard start capacitor installed piggy-back on the A/C unit may provide the extra kick needed to start some of the compressors on the larger units. Larger generators like the honda 3000eu are just to heavy and cumbersome for small boats.

 

[Hermit Scott]

AC

Benny
The place I was motoring was like a neighborhood with chanels cut in between the streets. You can see a pic of them on my myspace. There weren't any currents in there. But I understand what you are saying. There was a pretty good breeze and at times I would be going 4 mph. I need to learn the marine features on the gps I have so I can see exactly how fast I am going in knots.
The AC unit is a small one, I think. My guess is around 6 to 8 amps @110V.

 

[Bill Roosa6491]

Gensets and inverters

Hi Benny
You will not be able to use both your genset and inverter at the same time. the alternating current each produces must be "in phase" or you will have some smokin equipment somewhere. There are gadgets that can tell you if they are in phase and synchronized but as soon as you put a motor load on the system the individual power sources (genset and inverter) will start to loose sync due to the different ways they handle inductive loads.
Unless you are going to run lots of other electrical devices that take a lot of current it is probably better to just run the AC with a diesel motor. The boat motor is handy as it also charges your batteries, heats your shower water..... once you have the cabin cooled down for the evening you can use a fan.
A word of advice on admirals that want AC while under way, they don't spend much time on deck admiring the view or helping with the sail trim or helm so .......
It is a whole lot less work to leave her ashore and buy a 12 volt fan

I have found that an inverter running a plain old window fan stuck in the companionway works GREAT and does not add horribly to the energy budget.

 

[BrianW]

Hermit, check your setup on your GPS. It should be able to read speed to the nearest 1/10th. It may be set up to read out no decimal points. BrianW

 

[sailaway78]

I have laying around

I recently replaced a CDI furler. Have some pieces of the old one laying around that I have no need for, and have been putting off throwing them away. If you have one of the older, large model of CDI furler, I have the bottom bearing, a couple of decent foil pieces and the top fitting where the halyard goes through. None of these is any longer available from CDI, and if you can use any of them, they are yours for the cost of shipping.

 

[Hermit Scott]

Nice N easy

Thank you very much for that offer. I am not sure what type of furler I have, but I am going to my boat friday. I will take some pictures of it and send them to you. I will gladly take you up on that generous offer if they are parts that fit. If you have a paypal I can send it that way, anyway you prefer is ok by me.

Bill,
I don't want to go sailing with out my wife. If she wanted an extra bedroom built on top the deck, and that is what it took to have her with me then I would build a bedroom on the deck. I don't care about how much work I have to do. I bought this boat for my wife, my dog and me to sail to the Bahamas. She is the purpose of the boat not a problem to be dealt with.