April 2013 – Salty John : The Blog

Most of you will, from time to time, tow your inflatable dinghy behind the mother ship. There’s nothing wrong with this, we’ve done it many, many times and have never lost a dinghy or its contents. (On the other hand, we once lost all our snorkelling gear when one of our rope davit hoists failed and the dinghy was left dangling by one end – but that’s another story).

Towing an inflatable dinghy is best accomplished with a towing bridle that attaches to the dinghy at two points on either side of the bow. This helps to ensure the dinghy is pulled in a straight line and doesn’t yaw about crazily. 

The towline must float, obviously, or Sod’s Law will dictate that it’ll get wrapped round the rudder, propeller or both. So the towing bridle needs to be polypropylene line or it should be buoyed with one or more floats.

In fresh conditions very light inflatables are prone to becoming airborne. It’s true that leaving the outboard motor on the dinghy provides useful weight to counteract this tendency, but a better alternative is to partially fill the dinghy with water and keep the outboard safely stored on its pulpit bracket.

I like to use quite a long towline if there’s a following sea, adjusting the length to keep the dinghy one wave behind – I find this minimises jerking on the line and also prevents the dinghy colliding with the stern of the boat. An alternative favoured by some is to pull the dinghy right up to the stern – how successful this is depends to a large extent on the shape of the transom.

In rough conditions there’s no really satisfactory alternative to stowing the dinghy aboard – davits are great if the mothership is big enough to accommodate them, or lashed to the deck, or deflated and stowed in a locker. 

In the anchorage the dinghy is prone to nudging the boat annoyingly and is vulnerable to theft. Fastening the dinghy tight to the quarter with bow and stern lines keeps it under control – just make sure you fender it well. As a defence against theft, though, you really need to get the dinghy aboard – or at least hang it, horizontally, clear of the water on a halyard.

Dinghies are an absolutely essential adjunct to the cruising life but they can be a real nuisance – having the right handling system and accessories such as a towing bridle and webbing lifting slings help hugely. Check out the Salty John shop for both.

For many years we produced the Tiller-Hand, an adjustable tension tiller lock. It sold very well but when our molding tool was stolen we decided to discontinue the product rather than invest in a new one. 

There are several tiller locks on the market, some slick and professional, others that would make Heath Robinson cringe. Just Google ‘Tiller tamer images’ and you’ll see what I mean.

A piece of bungie cord across the cockpit and lying atop the tiller will provide enough resistance to stop the tiller moving in benign conditions. Should you decide to design your own on this principle just be aware of the dangers of working with super strong bungie cord without the proper training.

The marine VHF band runs from 156 MHz to 163 MHz. Most, but not all, VHF antennas send and receive over this entire band – they have sufficient bandwidth to perform at both ends of the range. But the performance, the quality of the signal, drops off towards the extremities of the range. This effect is less pronounced with top quality antennas and worryingly obvious on those of lower quality.

AIS optimised antennas were introduced to provide better performance at the higher end of the marine VHF band where the AIS signals reside – 162 MHz. But, if you want to use your AIS antenna as back up for your radio antenna you’re going to want to be sure that by optimising the performance at one end of the band you’re not going to jeopardise performance at the other end, where Channel16 resides. 

Well, you can rest assured that the new AIS optimised version of Metz VHF antenna has the quality of bandwidth to ensure it will perform well as a back-up radio antenna. 

However, I continue to recommend that if you are ever going to use your AIS antenna to replace your radio antenna, go for the Metz Manta. If your AIS antenna is never to be used to back up your radio antenna, go for the Metz AIS optimised version. 

You’ll notice a new link over there on the right taking you to Amazon where my ebook of this blog is on sale for the princely sum of £4.99. 

It’s a compilation of 100 entries, mainly informative, some philosophical, some humorous and, I hope, all entertaining. Nearly all entries are illustrated with cartoons or sketches or photographs. There’s a table of contents that allows you to flick around from subject to subject as the fancy takes you.

Of course you can always just read the blog here – you’ll probably find half the entries in the archives. I guess what the book offers is convenient packaging!

Rudders on boats have been around since 1000BC. They were originally steering oars deployed over the quarter but evolved over time into the centrally mounted foils we are familiar with today. 

When you choose a production boat you don’t usually have the option of different rudder designs – you get what you’re given – but the design of the rudder will certainly affect the suitability of a particular boat for a particular function.

Cruisers have different priorities to racers, as we’ve discussed before, and the rudder will have a bearing on the suitability of the boat for these different activities. In both cases, though, the need to sail efficiently is a given and the primary goals of the rudder designer will always be to minimise wetted surface, minimise frontal area and provide the most turning efficiency with the minimum drag.

Where the racer and the blue water cruiser will differ is in how much mechanical integrity they are prepared to sacrifice for speed and efficacy. 

At one end of the spectrum is the unsupported, balanced, skinny foil of the out and out racer; at the other end of the spectrum is the barn door bolted onto the aft end of a full keel. In between are full and partial skeg mounted rudders and transom mounted rudders. 

A rudder is subjected to tremendous forces from the pressure of the water rushing past it – the designer has to get his sums right when deciding how to support the foil in this environment and then the builder has to be meticulous in implementing the design.

And then we must ponder the imponderables – hitting objects in the water and taking the ground. Hot shot racers don’t anticipate hitting things and certainly aren’t prepared to sacrifice performance for a design that anticipates such an unlikely event. On the other hand, cruising folk do anticipate collisions with under water objects and running aground, deliberately or otherwise. So your rudder has to be fit for purpose.

When we first unstepped the masts on our 41’ ketch there was a coin under each mast. The boat had been owned at one time by a missionary couple who carried bibles to Central America from the USA and, appropriately, one of the  coins was a US half dollar dated 1973, the date the boat was built, and the other was a Guatemalan coin of the same age. 

This practice of putting a coin under the mast has its roots in Greek mythology.  The theory goes that coins were placed there to pay Charon his fee for taking the departed across the River Styx to the afterlife should the vessel be lost.

To ensure our own safe passage to the afterlife we cleaned up the coins and handed them back to the rigger to be replaced when the masts were put back in. The next time we removed the masts we found no sign of the coins. 

Luckily we’d had no need of Charon’s services in the intervening period.

I like walking around marinas, there’s just so much to see and reflect on. As I stroll around I tend to settle on a theme for the day: Drooping spreaders, types of bow or stern, cockpit covers or whatever springs to mind on that particular day.

On a recent recce I was focused on bow rollers. It occurred to me that one of the things that distinguishes a proper cruising boat from a marina-hopper is the way her ground tackle is managed. 

A serious cruising boat will have a proper anchor handling set up including an anchor locker, anchor winch and a bow roller. Trying to deploy and retrieve your anchor on a regular basis without the right system makes this essential task a frustrating chore.

I’ve talked before about anchor winches, windlasses and capstans so let’s take a look at anchor, or bow, rollers.

The anchor roller shares the pointy end of the boat with the forestay chainplate, pulpit bases and rollerfurling drum so it needs to be well engineered to avoid conflict with these other essential bits of kit. Occasionally you find the boat builder has provided a combination stem head fitting that incorporates the roller and full marks to them for this. Most boats don’t have this luxury and the cruising sailor has to retrofit one of the many proprietary anchor rollers available.

On Adriana we had hanked-on sails so no furling drum to get in the way of a hefty single roller bolted through the foredeck. The cheekplates were smooth edged and deep enough to keep the anchor from sliding off the roller. It worked a treat. 

I like to stow the anchor on the anchor roller ready to deploy with minimal delay. On Adriana we could only stow one anchor ready for action so I’d still have to lug the second anchor from the lazarette when required, but at least we could do that while we were secure on the main bower. On our bigger ketch we had the luxury of a bow sprit and a substantial bow platform that accommodated our two big CQRs easily, as is the case with the boat in the picture.

Take a critical look at you anchor management system – it can make anchoring a joy when it’s right, a nightmare when it’s wrong.