teadaemon

So long as the seacock remains closed (and hasn't itself burst due to water trapped within it). If you don't notice that a pipe has ruptured or been pushed off a fitting, it might take a while after turning the seacock back on before you noticed that the boat was filling up with water.

Unless of course the builders or subsequent owners have adopted good practise and sealed the balsa or foam core with epoxy or similar when they cut out the roof vent, to prevent water getting into the core and turning it into compost (if it's balsa) or slurry (if it's polyurethane foam). Clive - just out of interest, is the balsa core used only on the decks, or is it also found in the hull (and if so is it below the waterline or not)? Not an Aquafibre, but earlier this year I saw what looked to be quite a decent motor cruiser (built by a yard on the Broads, though I won't say which one) that had the spongiest decks I've ever come across in my life. On investigation it was found that they'd been cored with lumps of chipboard, which had (unsurprisingly) turned into foul-smelling mush.

Now that is interesting, and not at all how I'd expect things to be. It would suggest to me that (assuming one wants to go through against the tide, in order to have maximum control at minimum speed over the ground) there's a much larger window of opportunity to go upstream than there is to go downstream. That's definitely information I'll mentally file away for future reference, thank you.

Some people are just odd. We had one group of customers arrive Saturday afternoon and go out on one of our best boats (Flight of Freedom, the only one in the fleet with a bowthruster). They then phoned the yard up on Sunday morning to say that they really couldn't cope with the boat, could somebody come and drive the boat back from the New Inn? What was even more strange was that they'd done canal boat holidays before, so you would have thought that they'd be familiar with staying on a boat, even if the Bure around Horning is a lot busier than most of the UK's canal network.

If a company runs 300 hire boats, sooner or later one of them is going to sink. (In fact even if they run considerably less, one can sink, as we found out earlier this year with Spirit of Freedom). IIRC, two boats from Richardsons have sunk (or come very close) this year, both of them due to collision damage below the waterline of one sort or another (if that's not entirely accurate, I'm sure Clive will be able to correct me). Given that the boats are built to the requisite standards, and that even with the best handover procedures not every hirer is an expert at controlling the boat, the risk of this happening is something every yard has to deal with, and shouldn't reflect badly upon them when it does happen.

I will admit that I don't bother with Blakes and Hoseasons catalogues as a rule - I did glance through the 2010 Blakes catalogue earlier this year and noticed the absence of yachts. (A big change from my early memories of the Broads, when it was possible to hire a yacht from Martham (2 yards), Ludham, Potter Heigham, Wroxham (at least two yards), Horning, Upton, Acle, and (for a while) St. Olaves.) From what I've observed over the years, in general the few yards that still hire yachts tend to have a fairly loyal customer base (and were always the yards with a reputation for hiring out decent boats), so not being associated with one of the two big agencies probably doesn't affect them too much in terms of current bookings. Unfortunately that customer base is beginning to age quite rapidly, and there don't seem to be too many younger people getting the bug for it - when I went out for the Friends of Hunter's Yard picnic a few weeks ago I noticed very few people younger than me (33), and most seemed closer in age to my Mum, who absolutely loved being able to spend time on one of the Hunter's yachts again, even if we did nearly disgrace the Friends by sailing up the slipway at Thurne dyke (fortunately the old instincts kicked in and we managed to get all sail down and come to a relatively graceful stop in ~100m, without harming any one or damaging any boat, including the one we were on (Hustler 5)).

Accidental or not, that's probably about as good a control as you can get without a very large laboratory. I'd be very interested in the results, whatever they show.

Well that reduces the possibility of my only current idea - that the bar anode is slightly more noble than the stern gear anodes and is therefore being protected by them. MG Duff have about as good a reputation for quality control as there is, so I'd probably look elsewhere before getting into testing all of the anodes against a silver/silver chloride half cell. How similar is the control in terms of proximity to other boats, shore power, etc?

Ok, it sounds like whatever's going on, it's not something easy or obvious. I do wonder if it's something to do with the composition of the anode (and/or all of the other anodes). Not particularly easy to test unfortunately. Since it doesn't seem to be working very well currently, I can't see how changing it's position could make things significantly worse, so it's probably worth a try.

You haven't had a definitive answer, because their isn't one. Cathodic protection is more of a black art than a science, and most of the serious research that's been done has been on large commercial vessels built from steel or alloy, which doesn't translate very well to small leisure craft built from GRP or wood. Examining things from first principles, if the fittings are bonded by a wire on the inside of the hull, and both the fittings and the anode are immersed in the same body of seawater, then as far as I can see, the fittings should not need to be within line of sight of the anode in order to be protected, as nothing is actually flowing from the anode to the fitting or vice versa, apart from the electrons travelling through the copper bonding wire (zinc, aluminium or magnesium ions are lost from the anode, and hydrogen is generated at the fitting, but the two do not need to mix or transfer across in order for the anode to do it's job of protecting the fitting). I would suggest that the next time your boat is out of the water, you (or your surveyor) should use a multimeter to check for electrical continuity between the anode in question and all of the fittings that are (or should be) bonded to it. It takes very little corrosion in the wrong place to cause significant resistance in the circuit, and it's a lot easier and more reliable than following all of the bonding wires and manually checking that all of the connections are secure. Also make sure that the anode is not coated with anything that might insulate it from seawater (you're probably well aware that zinc anodes in fresh water can develop a chalky deposit on them which significantly inhibits their effectiveness, even if they later return to salt water, and that painting anodes is a really, really, bad idea).

I am not a lawyer, and this is not legal advice. With that in mind, this would seem a pretty clear case of a latent defect - the faulty gate valve. In such a situation, the insurer would probably pay out, minus the cost of the gate valve or it's ball valve replacement. There is the possibility that they would then take legal action against the boat builder (or possibly a surveyor if the boat had been surveyed) for negligence in fitting the gate valve in the first place.

AFAIK, opinions on whether or not to bond skin fittings are divided. As a rule, American boatbuilders do bond all skin fittings, European boatbuilders don't. Having seem rampant dezincification (of both skin fittings and manganese 'bronze' propellers) in a boat that was less than 2 years old (it was possible to remove slices of copper from the skin fittings using minimal force on a scraper), I would tend to agree with you that bonding is a very good idea.

Whilst not ideal, I think I'd rather have a bronze (or stainless, titanium, or even plastic) gate valve than a brass ball valve. This is quite a worrying report, as I'm not sure how I'd detect the presence of brass skin fittings during a survey (it was noted that the fitting on the yacht appeared perfectly normal when given a scratch test to the outer mushroom, which would be my normal method). I have also heard of cases where moulds for bronze skin fittings have been sold on and used by other manufacturers to cast skin fittings in brass, which say on them that they're bronze - even less chance of detecting that something wrong before they fail.

Buying vegetable oil from a cash and carry (or any other source) and using it to fuel an appropriate diesel engine definitely does fall within the bounds of the exemption, there's no requirement that you use recycled vegetable oil.

As I mentioned above (but got missed out of the quotation), the exemption is only for small users (less than 2,500 litres per year), so somebody running a car might well use enough to have to pay duty, but somebody running a Broads cruiser or yacht probably wouldn't.

IIRC, there is an exemption from duty for those who make their own biodiesel, providing they make less than 2,500 litres per year (on the grounds that it costs more to administer lots of small users than is taken in tax). Obviously records do need to be kept, so they can be inspected by HMRC if necessary. Camelot Craft did run all of their diesel-engined yachts on biodiesel (they also had two with pure electric auxiliary engines, which worked well. We hired one in 2001, and only had to recharge once during the week, despite motoring a fair distance, rather than just under bridges and into/out of moorings).

If the engine continues to run after the fuel cut off switch is activated it means that either the engine is continuing to receive fuel, which seems to be what most people are suggesting as the problem, or that the engine is finding an alternative source of fuel - if so, almost certainly engine oil. Needless to say, the second option is not good (a worst case scenario is that the engine will continue to run, increasing it's revs until it blows up or shakes itself to pieces). Have you (or somebody else) topped up the oil recently? Is it possible that you might have put a bit too much into the engine? I'd suggest that since you seem to have checked for a really obvious, simple problem, it's probably time to ask the opinion of a qualified engineer (and check the warranty on your engine rebuild). I know this is probably a bad time to ask, but when you decided to shell out £3,500 for a rebuild on an engine that's at least 26 years old (AFAIK, BMC 1.5s were built between 1968 and 1984), did you consider a modern replacement? If so, was there a reason other than cost why you went down the rebuild route?

How well does you mudweight hold after being deployed in this manor? I've always been taught to let it free-fall (either dropped or thrown overboard) in order that it buries itself in the mud as deeply as possible, hence my comments about flaking out rope.

One of the boats I look after at work is an Elysian 27 with a manual trailer winch fitted at the bow for the mudweight. I have to say that it's definitely less than ideal, as to drop (or if you prefer, throw) the mudweight you either have to flake the rope out on deck before you let go, or let the winch spin at high speed, with consequent risk to life and limb. There's also the issue of getting the mudweight back on board - on this boat it hangs just below the bow, but that's not a situation I'm particularly happy with. A 12V electric winch will use a lot of power, so in addition to the cost of the winch, you'll probably also need to factor in some very thick copper cables, and possibly a dedicated battery (not to mention chain locker, chain, bow roller or fairleads, and some means of making the chain fast when the winch is not in use).

Actually, my personal preference would be for manual inflation only. This is because I can think of several instances where people have been trapped under an upturned boat by their auto-inflating lifejacket, but none where somebody has gone into the water unconcious and been pulled out alive. Also, lifejackets do significantly impede swimming (as distinct from just floating), and as a strong swimmer I'd prefer to keep that as my first option, activating the lifejacket only if I actually need it. Whilst on the subject of lifejackets, it's probably worth mentioning that a lifejacket without either thigh or crotch straps is worse than useless, as if it doesn't come off over your head when it inflates, it'll probably throttle you with the chest strap.

For interior joinery in a GRP motor cruiser, you can use pretty much whatever species of wood you like. Teak is traditional, but ridiculously expensive these days. Plenty of narrowboats have wooden interiors made from Ash, Beech, or White Oak. While species is not particularly important, the quality of the wood is. 'Pine' from places like B&Q is often of pretty terrible quality (huge growth rings, grain runout, large knots, multiple pieces glued together, etc) - if you're doing anything that's going to be seen, it's worth taking the time and cash to get decent wood to start with. Not only will the end result look better, it'll be a lot easier to achieve.

I hope Clive won't mind me briefly hijacking his thread, but when the subject of surveyors comes up I feel obliged to make comment. No survey on any boat of this size (or even one a fair bit smaller and less complicated) is guaranteed to find everything that may be wrong with that boat, as a survey is a non-destructive examination of those parts of the boat that can be seen by the surveyor. The best the surveyor can do is tell you what they've seen, and what they haven't been able to see (which is why so many survey reports have long lists of areas that were inaccessible and therefore not surveyed). My personal advice to anyone contemplating buying a traditionally constructed wooden boat is only to do so if you enjoy owning, using, and maintaining traditionally contructed wooden boats. If you just want to go boating, then GRP, steel, ferrrocement, aluminium, or indeed modern wood/glass/epoxy composites (whether cold moulded, strip planked, glued lapstrake ply, or any other modern method makes little difference) can all be used to make decent boats that will require less maintenance, leaving more time and money for boating. Having said that, sailing a wooden boat is (in my humble opinion) totally different to sailing one built from anything else, and if you've got the bug for them then no amount of advice is likely to stop you from wanting one. Actually, given that maintenance costs are roughly proportional to displacement, then instead of the GRP hull/wooden top combination, another option for those that like wood but can't afford the time and money to maintain a large wooden boat is to have a large GRP boat with a small wooden tender. Ok, as I'm starting to ramble I should probably finish up and let everyone get back to admiring Broadsventure XII, much more sensible than reading my inane blather.

There's quite a few similar things around these days, when I last needed something similar I used something calling itself the Ultimate Boot Disk - a bootable CDR packed full of various utilities and with a fully-functioning version of Linux available for more complex fiddling around.

That row of traditional sailing boats has me intrigued, any idea what the rig looks like under sail? (I'm thinking they might be lateen rigged, but it's difficult to tell with the spars and sails stowed as they are in the picture.) Any idea what they're currently used for? (Originally I'd guess they were for fishing or shellfish/sponge diving, but whether any of them do that now is another matter.)

We did the Caledonian Canal for our honeymoon in 2005, hiring a Moody 28 from West Highland Sailing. I have to say that whilst I did enjoy the week, we did precious little sailing (head winds all the way to Inverness and back again), and after the initial novelty of sailing (motoring) through a mountain range, I found the scenery to be somewhat monotonous, albeit on a grand scale. I don't regret going, but to be honest I probably wouldn't want to go back. The BW mooring pontoons were good, and the shower/toilet blocks regularly spaced and of high quality. the pubs/restaurants we went to were also of high quality, possibly because tourists on boats are a relatively small part of their business compared to the large number of land-based tourists (n.b. this does mean that the larger lock flights at Fort William and Fort Augustus are replete with gongoozlers).