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Poo tanks and Aquadrives

I need to say before I begin that this blog might be borderline nerdy and maybe even a bit dull if you don't have a narrow boat. Don't say you weren't warned!

Since we bought Umbrellas in January she's been tucked up in her marina home on the grand union. We're champing at the bit to get going but there is some essential stuff that needs doing which is beyond my limited skills and experience. We're very lucky this year to have some money and we want the work done right. Unfortunately none of the work is cosmetic so Umbrellas won't look any different but we will hopefully end up with a working, reliable boat.

Of course we have a huge to do list of things we want to do to Umbrellas but we're also very keen this shouldn't detract from getting out on the water because that's what we bought a boat for.

Well, here she is, on blocks at the boatyard ready for work to begin.

We are very aware that this boat owning thing is a huge learning curve. Umbrellas isn't a rental boat so anything that goes wrong isn't someone else's problem it ours. So we want to understand the detail of the work that's being done to learn as much as we can about Umbrellas. Anything we learn must make life easier in the future.

So here's the list of stuff being done, and as always I'm always grateful for any comments. Fellow narrow boaters will hopefully be interested and may well have advice, a view or perhaps just a word of sympathetic encouragement.

Poo Tank - Umbrellas has a waste tank that is part of the boat, built into the hull when she was built. It's under the main bed and is huge (at least compared with the tiddly things we're used to on sailing yachts!). No idea how big, but rough maths suggests at least 4-500 litres.

The problem is that the survey found a hole in the top of the tank which I'm told is an issue with steel tanks. Over time condensation on the inside of the top of the tank causes rust and the ultimate failure of the tank. The options to fix this are expensive, replacing the tank is very difficult (it's integral with the hull), putting in a plastic tank instead is also not easy. Replacing the tank with a cassette toilet would probably be the best (and lowest cost) option.

We bought Umbrellas with our eyes open and knew about the issue with the waste tank, but for now we've got lucky. The hole is repairable with a metal plate welded on. We will need to deal with replacing waste tank in the future but this fix gives us some breathing space. At the moment don't even know whether we'd rather have a pump out or cassette toilet!

Aquadrive - "Umbrellas has an Aquadrive", says the surveyor, "ooh", says I, "that sounds fancy nancy". "It is", says the surveyor, "and it's worn out". "ooh, is that bad?", says I. "Not great, the part costs over a thousand pounds", says the surveyor. "Bu**er", says I, "plus VAT" says the surveyor. This isn't a surprise, Umbrellas is over 20 years old.

I'm not sure Aquadrives are that common so I thought I'd better try to understand what one does (my current knowledge is akin to a toddler pointing at the thing and asking "what's that?").

Here's what I've learnt using a couple of pictures which paint a thousand words.

Whilst this isn't what it looks like on Umbrellas, the pictures make it clear what an Aquadrive does. With an Aquadrive the alignment of the shaft from the engine to the propellor is not critical.

I'm told there could be an option for Umbrellas of ditching the Aquadrive, but the cost of convertion might well be the same as replacement. So the die is cast, a new Aquadrive it is.

Oh, and as they're pretty worn we may as well replace the engine mounts at the same time!

Through-hull sink drain

The bathroom sink drain is ropey, and as the title says is a through hull fitting. Of course it's not below the waterline, but nonetheless any through-hull fitting in my book needs to be water tight and robust. So it's being sorted, along with the kitchen drain which ain't much better.

Toilet waste tank outlet-inlet

Another learning curve, and another 'toddler' question from me. Why does a narrow boat waste tank have two pipes? The answer is one's to pump poo out, the other is a breather pipe to let air in. Of course! Anyhow these are very rusty where they're bolted to the deck, so much so that water's been getting in and making the bed mattress damp. Obviously this is a priority to sort before we start cruising.

Bilge Pump

Not working, need a new one. I'm not a massive fan of bilge pumps, they're not very effective with big leaks (a scared man with a bucket is more effective), but they will deal with smaller leaks, especially when you're not there. So Umbrellas is getting a new automatic bilge pump.

Tiller top bush

Just a nylon bush, but it is worn and narrow boat steering is loosey goosey enough as it is. So best replace it.


Most of the blacking was done when Umbrellas was surveyed, but there is a bit at the top which needs doing to finish the job.


Usual stuff, the engine needs servicing and I've asked the boatyard to check the heating and hot water. The engine is a 38HP Isuzu which we're hoping will work for a good while yet if looked after. The heating is of course an Eberspacher which I think looks like this.

I searched for at least 5 minutes and couldn't find it. Wonder how big it is? From what I can understand the thing not starting is the biggest problem so the boatyard will check/replace the glow pin (assume this is like a mini glow plug?) which I assume is the most likely thing to go wrong.

That's it, once all that's done we're hoping for a reliable boat that's as smooth as silk, doesn't sink and has all the important stuff working (especially the toilet!). We know there will be other stuff that goes wrong and we will have a very long to do list of improvements we want to do, but this gives us a good starting point to enjoy our cruising adventures.

More soon.

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