mooring buoys and maximum length & cruising speed

Hello everyone,

Even though my wife and I are going to be chartering for the next few years, I have already started researching which trawler would best fit our needs.

I have 3 questions, two are related to each other.

First, I have been told the maximum length for mooring buoys in the Pacific northwest is 45'. Is this true and does this refer to the length overall, the maximum length, or the reported length by the builder?

Second, how many people consider this as an important variable in choosing a trawler?

Lastly, I read in the most recent issue of Passagemaker that it is bad for the engine to be consistently run below the intended cruise speed. Our preference is to cruise for relaxation and fuel efficiency (usually around 5 knots or so). Some trawlers get great fuel efficiency at 4-5 knots but if their intended cruising speed is faster would this be a problem? The example they gave was an American Tug 435. Passagemaker said at 7.5 knots the 435 would burn 4 gallons an hour but that even at 4 gallons per hour, the engine is intended to cruise faster and increased maintenance and decreased engine life would be consequences. What do you all think about this?

Thanks! Kirk

I don't understand your question about moorings, but I can tell you there are plenty of boats used for cruising that are much longer than 45 feet. Dock space does get to be a problem, but at my 69' LOA, we have always found satisfactory reservations by planning ahead, and don't really mind anchoring out, either.

As far as damaging an engine by running without enough load, it depends an awful lot on the engine. Certainly true for 2-stroke Detroits, but much less so for modern 4 strokes, especially if the engines are brought up to 90% load/rpm for 10 minutes a day. I run my engines (QSM11's) at about 1,060 rpm (35% load, 3.5 - 3.8 gph each, 8.7 knots) 95% of the time (and usually, but not always, open them up every day). Without about 1500 hours on them, they seem to be in great condition.

In the Washington State marine parks, at least in the San Juan Islands, the maximum allowable length on the mooring buoys is indeed 45 feet. I don't think the park rangers get all wrapped around the axle on how one defines 45 feet. They would probably go with the manufacturer's stated length (Grand Banks 36, Nordic Tug 32, DeFever 46, etc.). If they had heartburn over this for some reason, they'd probably get out a tape measure. But I doubt it would ever come to this.

But if you plan to use the mooring buoys in the Washington marine parks, you'll need a boat 45 feet long or less. Anything bigger and you'll need to anchor.

Rafting is allowed on the Washington Marine Park buoys but the number of boats per raft is limited by their length. The length and number of boats limitations are posted on the buoys.

The mooring buoys in British Columbia's Gulf Islands marine parks are of two types. One is for boats 30 feet or less in length, the other for boats 40 feet or less. The maximum length is posted on the buoy. Rafting is not allowed on any BC park mooring buoys.

So if you plan to use the mooring buoys in the Gulf Island marine parks, you will need a boat that's 40 feet or less long. I have no idea how strictly these rules are enforced-- our boat is 36 feet long so is not a problem. We have never encountered a BC mooring buoy that has a posted length limit of 30 feet, but since they are described in the official publication about the BC marine parks, I guess they exist somewhere in the system.

While there is no stated maximum boat length for the docks in the Washington State marine parks that I know of, there is for the BC Marine Parks. It's 36 feet. Again, I don't know how rigorously this is enforced. It do know that some marine parks in the Gulf Islands have a seasonal park host. Some of these that we have met over the years lived on their boat at the dock. So I suppose in these instances, the 36' rule would probably be fairly strongly enforced.

Of course the other consideration is that many of these docks are in rather shallow water. In some parks, that alone tends to restrict the size of the boats that can use the dock. At Sucia Island in the San Juans, for example, at low tide on the docks in Fossil Bay it's not uncommon for keeled powerboats in the 36-40 foot range like Grand Banks or our friends' lobsterboat to sit on the bottom. Same thing with sailboats.

Regarding running a diesel slower than it's "normal" cruise rpm, there are a lot of variables involved. The engines in our twin-engine boat are happiest in the power range of 1500-1800 rpm. 1650 rpm gives us eight knots, so that's the rpm we use. While our boat's semi-planing hull will go a lot faster if the power is available, the drag and thus the fuel consumption will go up dramatically.

A late model Grand Banks 42, for example, with its two stock 400hp-plus Cat diesels, will happily cruise all day at about 9 knots with a combined fuel consumption of about 7 or 8 gph. However, the power available will push this boat along at some 15 or 16 knots no problem. The fuel consumption at this cruising speed will be some 23 gph.

Right now diesel fuel is free in the overall scheme of things, so if one has a boat like this, this is the time to go zooming and booming. But when the fuel prices go back up to $4 to $6 a gallon--- which is where I hear in my industry the prices will land when they start back up again-- that higher cruise speed will carry quite a price.

Good friends of ours have a 36' custom lobsterboat fitted with a Cat 420 hp diesel (turbocharged). This boat is intended to be cruised at 15 or 16 knots. I don't remember what the fuel consumption is at that speed--- I think it's about 12 gph.

When diesel prices went up a lot a few years ago and stayed there, our friends started cruising a lot slower, 8-9 knots. The fuel consumption dropped a lot. Our friends kept an eye on the temperature gauge to make sure the engine wasn't running too cool, which is the real issue with running a diesel at low power.

Also, on the advice of the very good diesel shop we both use, they run their engine at it's "normal" 15-16 knot cruise rpm for 15 minutes or so at the end of every run tp get it up to it's full operating temperature and "blow it out." This is apparently pretty important to do to ensure the continued health of the turbocharger.

There Is no standard size restriction on state or provincial buoys. Some may be as little as 30 feet. Some could be limited to two vessels of 28 feet. Others may be 45 feet. You need to read the markings on the buoy to make sure your boat is within the stated limit.

Enforcement depends upon the agency that "owns" the buoy. Some park rangers are very strict, some you will never see. With Washington State Parks you are expected to take your dinghy to shore and deposit a registration card and the fee in a lock box. In British Columbia they more often make the rounds in early evening and will knock on your hull and except payment.

No one I know made their boat choice because of size limitations on mooring buoys. Make your choice on what works for you and your crew. And remember, if your boat is too big for the available buoys you can always anchor.

Steppen said:

No one I know made their boat choice because of size limitations on mooring buoys.

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It can happen. Acquaintances who planned on buying a GB46 switched their plans to a GB42 precisely because they intended to use the San Juan park buoys a lot.

But I suspect this sort of thing is very rare. And while the State Parks folks are increasingly leaning toward not allowing anchoring in certain portions of the marine parks and/or at certain depths, so far that hasn't been enacted, at least not to my knowledge. So if one has a boat that's too large for the buoys, anchoring in the parks is still an option.

mooring buoys and maximum length & cruising speed

Although on the other coast, available mooring length was a large consideration in my boat search. With over a 15 year wait for a mooring, I lucked out and got a spot for a 36' boat. No more. My boat is 33'4" overall. Couldn't have gone much bigger.

So keep in mind where you're going to keep the boat when you're not using it. Not just where you will be cruising. You will likely be Spending MUCH 'moor' time at your Home Marina/Harbor than at a state park.

It's unfortunate that the max limit is 45 in Washington and above, we are at 55 and do like to grab a mooring on occasion. Anchoring out is just fine with us however.

Keep in mind the cost of moorage as well, most marinas have a sharp rise in prices as you exceed 50'. for example, Cap Sante in Anacortes goes from $570 monthly for a 46' foot slip to $820 for a 57' foot slip. That's every month for the life of the boat so it does add up. We found this to be true while cruising as well, our <45' friends would be boasting about the cheap rates while we were spending usually more than we budgeted for our 55.

As far as damaging an engine by running without enough load, it depends an awful lot on the engine. Certainly true for 2-stroke Detroits

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Certainly not true, actually.

Why tie to a mooring bouy? Did you put down its anchor? Do you know when its gear was last inspected? Unless you can trust it to hold you should it come to blow, you are better off to anchor.
In Montague Harbour, I have seen mooring bouys on the beach after a blow, having pulled all three of their concrete 1/2 barrels ashore with them. I don't know if there were boats attached when these bouys headed shorewards, but the sight was enough to keep me from any desire to use them.

koliver said:

Why tie to a mooring bouy? Did you put down its anchor? Do you know when its gear was last inspected? Unless you can trust it to hold you should it come to blow, you are better off to anchor.
In Montague Harbour, I have seen mooring bouys on the beach after a blow, having pulled all three of their concrete 1/2 barrels ashore with them. I don't know if there were boats attached when these bouys headed shorewards, but the sight was enough to keep me from any desire to use them.

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Saw a similar sight at Sidney Spit, although the in that case the line parted. The vessel that was moored to it barely escaped as her captain felt the hull bouncing on the bottom and was able to fire things up and get away.

koliver said:

Why tie to a mooring bouy? Did you put down its anchor? Do you know when its gear was last inspected? Unless you can trust it to hold you should it come to blow, you are better off to anchor.
In Montague Harbour, I have seen mooring bouys on the beach after a blow, having pulled all three of their concrete 1/2 barrels ashore with them. I don't know if there were boats attached when these bouys headed shorewards, but the sight was enough to keep me from any desire to use them.

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I agree, on the subject of mooring balls on the beach. I find it very hard to believe a ball could haul a concrete anchor to the beach. So if you saw it there a boat must have "helped " it.

I personally have a real problem trusting mooring balls for this very reason.

There are a few places in BC where it can get crowded and mooring if you get one will work out well. In the Summer months few storms. I have seen boats up to 50 ft on moorings with no apparent problem with park ranger who collects fees every evening. I doubt 55 0r 60 ft would work. I often use a mooring. If you put a tape to my boat anchor roller to end of floating swim platform you get about 51 ft. However we have a low air height and are not a bulky boat 34.000 lb. A forty five foot GB is a lot more boat.

Re what rpm a motor is run at; There have been many posts and too much controversy on this site and others. Older two cycle engines and engines run at idle for long periods do suffer from lack of higher load running. Enlightened management of a diesel engine using lower load rpms for low speed economy with higher load for 10-15 at end of run will not hurt the engine and most likely add to its life. There are too many other things that can kill a diesel engine to worry about slow cruise commonly used on SD boats with a wide cruise range. The full electronic common rail engines are probably fully capable of adjusting to the low rpm. One caveat the operating temperature no mater what rpm should be in the proper spec. range On some engines an adjustment may be needed..

Our public moorings are provided free, largely by National Parks, and carry a time and boat length restriction. They are maintained (I`ve seen them do it) in nice places where it is often very deep, and are sought after. I think the length restriction iis getting longer, some 15M have become 20M, so things may yet change Kirk.
In a couple of places we have large private mooring fields where it is well accepted (probably not by all) that boats use other people`s moorings. Others have picked up my home mooring when I`ve been off it. The "rule" is, if the owner returns, you get off. Though one Club tells its members not to insist on people vacating Club moorings at night etc, and to just take something else.

Kirk,

When we bought our boat (my first diesel boat) I was told that the engines (3406C Cats) like to be cruised at 80% throttle 20% of the time. That calc's out to be around 1750 rpm's and that puts us on plane at around 22kts-24kts.

We usually cruise much slower than that, around 1000 rpm's and that puts us around 11kts-12kts, and often at just above idle, around 850 rpm's which puts us around 9.5kts-10.5kts.

That works for us and our engines, but might not be good for any other engines.

Our first choice is anchor out but in some areas like Bonaire, no anchoring, moorings only. When we're on a mooring, we treat it the same as anchoring. We back down to make sure we're not going to drag and to confirm the mooring hardware is strong enough for a good nights sleep.

GFC said:

Kirk,

When we bought our boat (my first diesel boat) I was told that the engines (3406C Cats) like to be cruised at 80% throttle 20% of the time. That calc's out to be around 1750 rpm's and that puts us on plane at around 22kts-24kts. ...

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Is that 80% of maximum fuel consumption or 80% of maximum RPM?

When we're on a mooring, we treat it the same as anchoring.

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This. We have used moorings extensively up and down both coasts of the USA. The only issue in dozens of moorings and a few hundred nights of full time living aboard, was at Vero Beach, where the loop on the painter literally broke off in my hand. Always verify with the harbor master that the mooring is rated for your boat size, and whenever possible, use your own lines.

Larry M said:

.. When we're on a mooring, we treat it the same as anchoring. We back down to make sure we're not going to drag and to confirm the mooring hardware is strong enough for a good nights sleep.

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Good idea, thanks Larry,never thought of that. One night on an opm (other persons mooring), for 2 hours the wind pulled the buoy of out the water and parallel to it. I was nervous, the ground chain to the block must have been fully lifted.

Thanks for all the excellent replies, I appreciate the effort!

I like the idea of backing down to test the mooring hardware. I am going to start testing them prior to relaxation.

It seems running the motor(s) near 90-95% of full throttle for 10-15 minutes in the later part of the day is a good idea. 80% throttle 20% of the time also sound like a good approach.

Thanks everyone!

Kirk

If you do go to the San Juans I would also recommend buying online a season pass for your boat. Will save you big $$...

Mooring buoys here almost always have a line attached. The IG has a high bow, so we carry what I call a "strop", a line with a loop one end to attach to the loop of the line off the buoy, extending the length, to reach my bollard/cleat.

so we carry what I call a "strop", a line with a loop one end to attach to the loop of the line off the buoy, extending the length, to reach my bollard/cleat.

No matter what the boat configuration using a line thru the mooring line eye is considered polite , as any chafe is to your gear , not the mooring.