St Sampsons and diesel

After a few very chilled days enjoying the island, the sun (but not the cold winds) and doing a bit of boat cleaning / polishing too, Monday morning meant getting mobile again. We had a slot booked to get diesel in St Sampsons Harbour where you tie up to a pretty elderly floating pontoon in the corner of the harbour around high water (it dries out....) and get filled up from a road tanker. Way way cheaper than using the pumps in St Peter Port (and nicer people serve you too!)

So, a short (2.5 nautical miles) trip arriving just before Kevin the Rubis tanker man. 2,588 litres of fuel later, the boat was floating a little lower in the water but ready for many many miles of travel. (She holds 5,500 litres, good for way over 3,500 nautical miles if you go at a sensible pace). The best bit was the 60ppl price. If we'd had a fog free day last Thursday, it would have been 3p a litre more so we ended up thanking the fog! Funny world, isn't it..... A reminder to all the other boaters who fill up at Boatworks + in St Peter Port harbour - their diesel was 17ppl more expensive than the nice tanker man, and he chats and smiles quite unlike the grumpy lot here. When you come to Guernsey for fuel, ring Rubis and be nice to Kevin!

We had decided to trundle back to St Peter Port afterwards, to clean up the other side of the hull. The Port side tends to get neglected as the walkway is to starboard and so we always moor up "that side to". Even giving the port side a good wash is difficult in a marina as there is rarely space to get a dinghy between us and the neighbours.

Having washed off the worst of the grot, some polishing in the SUN followed. Riotous life eh? Still, it has to be done once a year and this is the once. Great setting to work in and warm for a change too. We like this life.

Fog - and lots of it

On Wednesday, the fog / mist hung around most of the day. This morning, about 5am, it was just lovely - a real pea souper.. Visibility in the harbour at St Peter Port was about 70 yards and then dropping to more like 10 intermittently. Did we fancy going into St Sampsons to get diesel at 7:10 unable to see anything and then making a channel crossing glued to the radar or did we fancy turning over and sleeping a little more? The answer really shows the difference between vacations and liveaboard life. On holiday, as the boat is well kitted out with great radars, plotters, PC navigation, AIS etc and has redundancy built in, we would have said: "OK, a tiring 12/18 hours to get to  Dartmouth / Falmouth but let's do it". Now, why bother? The fog is going to disappear in a day so....

The boat is built to manage heavy seas and kitted out for relatively simple navigation and watchkeeping in poor visibility / at night. Like most south coast boaters, we've spent many hours trundling along in thick fog....  However, it is tiring sitting watching the radar especially when crossing the busy shipping lanes and the crew doesn't like trying to spot pot markers out to sea in the fog much either. If something goes wrong with equipment, you have a harder time in the fog so, another couple of hours sleep instead. Tough life...

We moved the fuel appointment to Monday as the shipping forecast had "rough" for the middle of the English Channel on Friday with the waves right on the nose of the boat if we headed for Falmouth. No big pressure to leave or get anywhere at any specific time, so we will stay put, do some more polishing (poor boat really looks sad after the winter snow and ice, then the early season rain) and enjoy the Guernsey pace of life a little longer. No more cruise liner visits planned so I think we get our island back too.

Guernsey life......

Well, owing to the strange high tide times, the diesel top up was booked for Thursday at 7:10am. A great excuse to spend some time exploring the town, island, local Waitrose (newish, enormous, wonderful!) and doing a bit more polishing. Also time to top up the petrol for the RIB and the little eggwhisk outboard for the small inflatable dinghy. Marine petrol at £1.06 a litre. Glad we had nearly dry tanks in the RIB when we arrived.

The pontoons in the harbour got busier during the week as the high pressure took over, the wind dropped and the French started to visit. Typical French yachts - scruffy, faded hull colours with a matt finish. Why do they not try to protect their investment a little better? Must ask the French people I know why houses, boats, cars all tend to get abused / ignored.  Their approach to boat maintenance is funny - using scouring powder on the shiny fibreglass isn't a good recipe for longevity.

On Wednesday, the P&O liner reappeared, think it is doing "taster cruises" from Southampton. Well, the town was again full of people who thought they were still on the liner and hence able to order others around. Felt like they were clogging up our pavements! The real shock horror is that the local bus service is about to discriminate against visitors. The £1 flat fare is going to be doubled for non residents and the famous no 7 bus that takes you all the way around the island for a quid will have a service cutback too. The locals are not happy - something for the ITV Channel islands service to run a major 3 hour special investigation into I reckon.....

St Peter Port

One drawback of the Nordhavn 47 is the amount of glassfibre to polish each year. As the weather had been disgusting when she was out of the water just before Easter (and the captain had been very ill...) , there was no chance to polish the hull. So, today we started. No further comment. The never ending task has begun for 2013. The town, which pretty much shuts on Sundays, was invaded by a lot of P&O cruise ship people who were ferried into the harbour from the ugly block of flats anchored just offshore. A good reason to avoid the town and do some polishing. If you have to do chores, a nice environment helps of course - looking from the mooring to Castle Cornet:

For the technical types, there is little to report. Engine room checks etc completed and nothing to fix or tinker with after the run over. Looks like we will need about 2,800 litres of fuel (gulp) when I call to book a road tanker time slot tomorrow. For the economically minded folks, buying marine diesel at the fuel dock in the main harbour is way cheaper than buying it in the UK. Having it delivered from a road tanker in St Sampsons ( a couple of miles north) is way cheaper still. We like that!

Studland Bay to St Peter Port (Guernsey)

This is a well trodden route across the channel that we and many others have used many times. Different before though as it was part of a tightly time-boxed holiday when our annual fuel fill up and few days in the Channel Islands was squeezed into the 2 or 3 weeks of freedom.

To try and avoid the worst of the foul tides around the north of Guernsey, and to arrive in daylight, we headed off nice and early. Well, early, maybe not nice. Lots of residual "slop" in the channel from the many days of strong winds but nothing that worried the stabilisers. Crossing the Traffic Separation area just north of the Channel islands was fun. The AIS screen was full of the big guys - much busier than we've seen for many years (maybe the world economy is picking up again??) and lots of course changes were needed to thread through them.

Arriving in St Peter Port we found a powerboat race underway with lots of tortured engine noises as the boats thrashed their way though some choppy waters just south of the harbour entrance. The arrival of the fast catamaran ferry from the UK added to the size of the waves they were battling - I think the island's osteopaths will be busy early next week.

The visitors moorings in the harbour were almost deserted - a first. We always reckon that a place is good if you have to go ashore by dinghy. St Peter Port is good.

Having spent several very chilled days in the Solent area, seeing friends, collecting a new baby outboard motor etc, the wind finally died down and the English Channel had a forecast that didn't have "rough" or "very rough" contained in it. The plan was to raid St Peter Port in Guernsey for better priced diesel as a fill up would get us all the way around the UK if needed. Carrying 5,500 litres has some benefits, the bill for filling the tanks isn't one of them of course

So, on Friday afternoon we left our mooring in Lymington (Dan Bran pontoon, great views and just far enough out of town to make the walk into the shops seem like healthy exercise too) and headed out of the Solent. The remains of n days of strong SW'ly winds combined with the Northerly today meant a nice "sloppy" sea for the run over to Studland Bay off Poole. Of course, as we arrived the sun went in and the rain started together with the usual wind squall that accompanies a shower. Great for anchoring when you have to be outside to check things and fit the snubber.

Still, it was good to be "on the way" to wherever we end up this year. Kind of felt like the start of the adventures to come. The Brighton / Solent time that we had enjoyed since retirement was good of course, but familiar territory stuff. The best part of the trip was the crew trying to get some pictures of the Needles rocks off the Isle of Wight that had a horizontal sea in the background. Sea conditions didn't help and about 20 tries later, there is still no nice image to post in here as a leaving the Solent landmark. Just this one:

Fuel Burn Stuff

Economical cruising – an interesting topic for the tekkies! You have the conflict of the optimum (=most fuel efficient) speed for the boat itself and the optimum (=most efficient operating speed and load) for the engine. Guess what, on many boats they don’t always meet up too well.  

With a full displacement boat like our Nordhavn (40 tons when full of fuel and water and cruising stores) it is pretty simple. The slower you go, the more efficient she is. However, if you travelled at around  2 knots all the time it would be pretty slow, lots of going backwards against adverse spring tides etc. You would also need a very small low powered engine to try and keep it loaded properly as diesels hate running without a proper load for long periods. Of course then you wouldn’t have enough power to push tides / wind when needed or to manoeuvre the boat either. So, like most things in life, it is a compromise.

The matching of the hull, engine and propeller is a complex science with some artistry in it too. If you want to read about it and become a real long distance motorboat design expert, read “Voyaging under power” by Robert Beebe. Only for the seriously committed boat people though.

As we have a fixed hull, propeller and engine combination we will oversimplify it to what speed the hull likes and what speed the engine likes:

The engine bit:  I was always taught that for a diesel to be reasonably efficient and for longevity, it has to be operated under at least 30% of the maximum designed load as a rule of thumb. Otherwise the engine just isn’t running efficiently – lots of “losses” from friction and ancillary components mean that the power actually produced compared to the fuel burnt is poor at lower loads. Of course, any engine also needs good bursts of full load to keep the cylinder bores clean and in our case to stop the dry exhaust stack from getting heavy soot deposits inside it. These are then sprayed around as nice wet soot blobs when she is started from cold. That really upsets neighbours in their shiny white go faster boats… So we aim to run at something over 35% load all the time and have at least 10 minutes each day at wide open throttle.

Some people have asked about running their planing boats at slow speeds and if the same still applies. Well, bad news. The typical high speed aftercooled engines hate "ticking over" for long periods even more. There are some interesting technical reasons for this (overcooling at low power outputs, exhaust gas temperature etc) but as we don't have an aftercooler they dont worry us too much!

The hull bit: If you read the books they can explain why a displacement boat has a so called “hull speed”. Any faster than that, you just burn diesel to make bigger waves and don’t go much faster. It is all to do with the square root of the waterline length of the boat. ie “longer is better / can go faster”. No comment.

Of course, you also want to travel at a speed when the boat rides comfortably. Not enough power / speed allows her to wallow about more and so you also have a trade off in ride comfort versus outright fuel economy.

Here is how our fuel burn varies with speed when the boat is full of fuel / water in calm seas:

RPM      lph         speed   MPG

                                               

1216       4.6          5.3          5.24

1410       7.3          5.8          3.61

1510       9.6          6.2          2.94

1575       9.9          6.4          2.94

1610       10.4        6.7          2.93

1703       12.5        7.1          2.58

1810       15           7.6          2.30

We tend to run at 1450rpm or so on longer trips as it keeps the engine reasonably loaded (35%)  and gives us sensible passage times (about 6 knots) and fuel burn (about 3.5 nautical miles per UK gallon).  Naturally this improves as you burn off fuel and the boat gets lighter. Wide open throttle gives us about 2350rpm and a wild 34 litres an hour burn at only 8.5 knots. See how it works?

Because we go slowly, we don’t need much power. On long runs the main engine is only running at about 65hp to give us 6 knots. That is why the little emergency “get you home” wing engine only needs to be 40hp. It can still push 40 tons of boat along in an emergency.

As a comparison, our old boat was a planning speed Broom 415. She weighed about 17 tons. At 20 knots, she managed 1.1 mpg. She needed 880hp to get to 31 knots when the consumption was 0.7mpg. That is why you have to go long distance cruising slowly!

Some more information about the boat and equipment - for trainspotters or people with time on their hands!

We bought our Nordhavn 47 early in 2009. She was a couple of years old, having been built for a man who kept her in Denmark.  That is relevant when you look at the equipment he fitted – the boat is unusual in having Thinsulate insulation in the roof lining area and the windows in the saloon and pilothouse are double glazed. Great news for liveaboards, avoids all the condensation that you get when the heating is running in cold, wet weather and makes the boat easy to keep warm in the depths of winter (or summer of course!)

She was fitted out ready for serious cruising with all the necessary kit based on good advice from the Nordhavn Europe team. Hydraulic stabilisers, redundant autopilot heads and computers, water maker, SSB radio etc. She was completed just as Furuno were switching to Navnet 3.  Luckily (I think), the boat had a suite of Navnet II equipment which has was  rock solid reliable.  We decided to upgarde it during the winter of 2008/9 not because it was causing trouble but because we feared that spare parts supply might become an issue in future and the old kit had good resale potential too. There was  a built in PC that ran Maxsea software which interfaced to the Furuno equipment. The delights of Microsoft – I thought I had escaped from all the compatibility issues and problems when I gave up working in IT! Her is the old style office:

for informationm on the upgrade to Furuno TZT2 kit look at http://rocklandlog.blogspot.com/2019/02/trashing-boat-electronically.html

and to see the final result, try http://rocklandlog.blogspot.com/2019/03/all-re-electroniced-and-broke.html

The boat has the larger pilothouse berth that can be used as an extra double for short term visitors if the forecabin is already occupied. This cuts down the seating area a little but there is plenty of space for 4 people in the pilothouse when underway.  If we were having another 47 built, I would go for the standard smaller berth though as we only use it for the “off watch” person on passages.

Luckily, she also had a full height Stidd helm seat fitted – most boats have a half height seat and when underway in the “rougher stuff” we really appreciate the extra support (age and bad back thing I suppose). The Stidd seats are crazy prices but just so comfortable on longer passages. We would smile and fit one to a new boat despite the bill.

Domestic equipment – again built for living on board. She was fitted with Miele appliances from new, including a slimline dishwasher that makes having guests on board so much easier.. The best part is having a separate washer and drier, no need to go to a marina launderette:

 

Entertainment is taken care of by a B&O system – remember, she was built for a Danish guy!

The best part (OK, in the Captain’s opinion the best part) of a Nordhavn is the engineroom. For anyone who has battled trying to access engines or fuel filters buried under floor panels in a boat that needs a slim contortionist to work on them, this is heaven. In fact, you can be ham-fisted and overweight yet still get to all the important parts of the engine, wing engine and genset. The access is great and encourages proper maintenance and regular checks. Our boat was built with an internal phone system so the captain can phone the galley for tea whilst working down in the engineroom. Getting the phone answered isn’t guaranteed of course…. There are two other great resources. The Nordhavn owners groups on Yahoo are a mine of information – many very experienced owners who have circumnavigated / crossed oceans in their boats. The second is the support from the Lugger (Alaska Diesel) factory training man. Known as “Lugger Bob” he is also a keen boater and offers advice and technical hints willingly – most unlike the approach from people like Volvo who don’t talk to customers and just  say “call a dealer out”. That isn’t too practical when you are mid ocean and linked only by sat phone!

The main engine (see link in the “useful stuff” section) is a marinised John Deere unit. For the tractor trainspotting types, it is a Deere 6068. For the rest of us, it is a big capacity (6.8 litres) block to make a lazy 170HP or so, slow revving and gives the impression of being bullet proof. Underway, it runs at about 40% load to push the boat along at her optimum hull speed for efficiency. So far, no Nordhavn owner has reported a major mechanical failure with one of these. Naturally as a prime mover, you need that. The engine is relatively low tech. No common rail high pressure injection, no fancy control systems, no supercharging, just a turbo to clean up the exhaust at higher rpm. The KISS approach!

The other big plus is that standard service parts and any replacement components are available via John Deere agricultural dealers. Sensible prices (sorry Volvo, Yanmar) and great logistics as they are geared up to supply parts for commercial users worldwide.