July 2013 – Salty John : The Blog

A head in the sand attitude to potential disaster doesn’t work on a boat. You need to plan ahead.

What if you lose the mast? You may have to cut the rigging and you’ll find this takes some doing with stainless wire – check that your cable cutters are man enough for the job. On all but the smallest wire sizes you’ll need ratchet, or even hydraulic, cutters. Do you have a spare vhf antenna? If so, can you rig it efficiently? A pushpit mounted vhf antenna, perhaps for AIS with a patch lead to switch from AIS engine to radio, is a simple way of providing redundancy for the masthead antenna.

What if you get knocked down? Will your batteries, floorboards, cooker and other heavy items become lethal weapons? Will lockers spring open and scatter their contents everywhere? Spend a few minutes looking around your saloon imagining what would happen if you were inverted. Lying on the cabin sole helps with this process.

Losing the engine isn’t usually a problem on a sailboat, except when you’re relying on it to get into your berth or through a cut in a reef. I once picked up a piece of nylon net around the prop as I was negotiating the entrance passage through the reef at Rum Cay, Bahamas. Fortunately we had the main up and it gave enough drive to get us through into safe water. Without it we couldn’t have carried far enough and might have been swept onto the reef. In confined quarters have a contingency plan in mind – where would you bale out to, could you execute a U-turn to get some way off, which is the least expensive looking boat to hit?  

When there’s the risk of running aground have a plan in mind. If you intend to throw the engine in reverse and you’re towing the dinghy make sure the painter can’t reach the prop. Warn crew that there might be a jolt – a man in the water is the last thing you need when you’re trying to cope with a grounding.

Plan ahead, that’s the seamanlike way.

These past few days we’ve been crewing on a friend’s boat, cruising the sound of Jura from Ardfern down to Gigha and back. We stopped a couple of nights in an interesting anchorage: Eilean Mòr, one of the McCormaic Isles which lie at the entrance to Loch Sween.

There’s room for two or three boats to swing on the hook in the tiny inlet which is completely sheltered from all directions except north. Ashore there’s a stone ‘bothy’ with a grass roof which was in the process of being repaired by volunteers and there’s a bit of a dock against which a couple of smaller boats could raft up. 

Some strategically placed iron rings have been set in the rock to accommodate shore lines to anchored boats should it be necessary to restrict swinging or give extra security. At one time there had been a large rock inconveniently located in the middle of the anchorage but it was blown up by military experts some years ago to the benefit of all. 

Inland there’s an ancient chapel built in the 13th century which contains a carved effigy of a monk, and further along there’s a monk’s cave dating back to the 8th century. As I understand it, the monk would climb into the dark and eerie cave to meditate and pray whenever he felt life was getting a bit cushy and a greater degree of penitence was required.

The island is uninhabited now but at one time would have supported a population of around thirty. They and itinerant fishermen and traders would have provided the chapel’s congregation.

The views from the hill are stunning and the birdlife is spectacular, and noisy. 

I’ve always enjoyed walking the towpaths of England’s canals and for the past couple of years I’ve enjoyed boating on them too. This has led to an interest in the workings of these watery ways and recently I’ve discovered the secret of the blocking pin.

A blocking pin is part of a clever arrangement that was used to help a horse pull a narrowboat out of a lock and be on its way up the canal with minimum delay. It took a considerable effort to get these heavy boats moving from a standstill so the boatmen were provided with this cunning device to give the horse a helping hand.

The blocking pin is a curved iron spike that looks like a hippo’s tooth stuck in the towpath just after the top gates of a lock and pointing away from the lock. The boatman would drop the loop in the end of his tow rope over this ‘pin’, take it back through a rigging block attached to the bow of the narrowboat and then forward again to the horse. This gave a 2:1 purchase, enabling the animal to get the boat moving with half the effort – like changing down a gear. This arrangement had the added advantage of keeping the boat in the centre of the lock, away from the stone lock sides, further easing the burden on the horse. 

Now the clever bit: As the boat moved past the curved pin the loop in the tow rope would slide off the pin and run back to the block where it would it would be stopped. Towing would continue seamlessly but at a 1:1 gear ratio. The equivalent of switching up a gear, automatically!

This may be old hat to canal boaters but for a salty sailor like me it was a revelation.  (Thanks to Brian McGuigan for the use of his photo)

Under sail with the engine stopped, does a fixed blade propeller create more drag when it’s locked or when it’s allowed to freewheel? The answer is unequivocal: There is less drag when the propeller is allowed to rotate. 

Scientists at MIT and at Strathclyde University agree on this. Michigan Wheel Marine, the propeller manufacturer, agrees. It used to be contentious, now it’s a fact.

So, we know we get less drag with the propeller rotating but there are other arguments for and against allowing the prop to turn:

Noise: The rumble from a rotating propeller can be quite intrusive, particularly if you’re off watch in a stern berth. Some people can’t stand the noise whilst others find it interesting; they like to judge the speed of the boat by the level of noise. 

Energy recovery: If you want to run a generator off the shaft it has to turn – simple.

Wear: Where there’s motion there’s wear and tear, if not damage, to drive train bearings and seals. 

Gearbox damage: One way to stop the propeller turning is to sail with reverse gear selected but it may damage your gearbox. 

It seems that Yanmar became so concerned at the number of requests they received for clarification on the best practice for their engine/gearbox combinations that they issued a directive: The gearbox must be in neutral when sailing or your warranty will be invalidated. If you want to stop the shaft use a shaft brake, they say, not our gearbox.

I have to admit that I sailed for many thousands of miles with my Yanmar 3GM30F in reverse gear to stop the shaft rotating and I never had a moment’s trouble.

If you have a Hurth/ZF gearbox you must not select forward gear when sailing forwards. Or reverse when sailing backwards, obviously. Apart from that, use the gearbox in reverse to lock the shaft or let it run free, it’s up to you.

With a Borg Warner Velvet Drive transmission you can do what you like with the gear lever, the prop will rotate anyway. You’ll need a shaft brake to stop it.

On some gearboxes damage can occur because the engine needs to be running to provide lubrication; with splash lubrication there isn’t usually a problem, so check the manual.

It boils down to this: If you are obsessed with squeezing out the last fraction of a knot under sail you need to let the prop freewheel. You’ll be happy to accept any wear and tear on your cutlass bearing and you’ll issue ear plugs to those that find the noise is keeping them awake. Or you’ll fit a folding prop.

If you’re worried about wear or can’t stand the noise you’ll want the shaft stopped and whether you do that by using the gearbox or a shaft brake will depend on your gearbox manufacturer’s advice, and whether or not you’re going to heed it. 

There are no hard and fast definitions of the various points of sail – no specific headings relative to the wind that tell you if you’re broad reaching or running, for instance.

To me it’s simple – when you can’t get any closer to the wind without luffing you are close hauled. When you fall off the wind a little from this point you are close reaching, off the wind a bit more until it’s on the beam and you’re beam reaching – the clue is in the name.

When the wind moves aft of the beam we get to a broad reach and then when the wind is roughly behind the boat we’re running. 

But, as with other aspects of sailing, there are complications; when you slack the sheets a bit from a close hauled course you can be said to be sailing ‘full and by’ and only after that do you get to close reaching. 

And close reaching is also called fine reaching, just to further complicate things for the beginner.

The other side of close hauled from full and by is ‘close and by’, which many call ‘pinching’ – trying to get even closer hauled than close hauled, resulting in too much luffing and a loss of speed. Full and by is often defined as sailing close hauled with the sails full – as opposed to close and by which is sailing close hauled with the jib luffing. 

Downwind you can get yourself into the perilous position of ‘sailing by the lee’, introducing the prospect of an unintended gybe if the helmsman is trying to work out what the hell ‘sailing by the lee’ means instead of concentrating on steering.

With more and more sailors having wind instruments to give them a precise heading relative to the apparent wind these points of sail may eventually become redundant or simply quaint. 

That would be a pity.

Don’t forget, you need to download my eBook (over there on the top right is a clicky thing); modesty prevents me from telling you what a good read it is, suffice it to say that you’ll be helping Leukemia research so there’s no downside even if the books a crock. Let’s get it back up to number one in the Amazon watersport section – you can do it! 


All VHF radios and good quality antennas use a PL259 plug as the means of attaching the coaxial cable. 

When you fit a PL259 to marine quality coaxial cable the most common problem is inadvertently shorting the centre conductor to the PL259 body. 

This is because the centre core on marine quality cable is stranded; when you feed the stripped cable into the PL259 it’s difficult to see if the stranded centre core has gone cleanly into the centre pin or if a few strands have been bent back into contact with the connector body.  

One way to solve the problem is by soldering the strands of the centre conductor together before inserting it into the PL259. Be careful, you don’t want a big blob that makes the conductor too wide for the hole in the centre pin.

If you prefer not to do that, here’s a tip: No matter what the fitting instructions tell you, when you strip the cable in preparation for fitting into the connector, leave a long section of bared centre core –  at least 30mm. Then, when you feed the cable into the PL259 body, you will be able to see that the centre core has cleanly entered the centre pin before the remaining cable obscures your view.

It will also be obvious by the condition of the centre core protruding through the centre pin that it has come through undamaged. You’ll now need to trim off the centre core flush with the end of the pin.

Remember, when correctly fitted there should be no continuity between the centre core and the body of the connector (with antenna and radio disconnected). But if a strand of centre core has been snagged you’ll see a short circuit between centre pin and body, in which case start again. 

Only when you’re happy that there is no short circuit across the PL259 should you solder the joint. Trust me, there are few things as aggravating as seeing that meter dial flick over to zero – no resistance – when you hold the probes across the pin and body of your neatly soldered PL259. 

Unsoldering is up there with getting toothpaste back in the tube – check before you solder.