Fluid levels

One of the delights and mysteries of narrowboating is the sheer quaintness of most boats. Realistically speaking, a horse-drawn narrowboat of the 18th century is just as functional as a diesel driven boat of today. And the diesel boat engine of today is really not that dissimilar from the hot-bulb engines fitted to narrowboats at the beginning of the 20th century. In fact, basic narrowboat technology really hasn’t changed at all since they were first fitted with diesel engines. Sure, modern boats are equipped with generators and batteries to power low voltage lighting, refrigerators and hair dryers and most boats are now equipped with Wi-Fi, but in most respects narrowboats remain very basic. Nowhere is this more evident than in the matter of fluid levels.

The fluid levels you must measure on a boat include diesel fuel, oil, propane, water and sewage. Additionally you might also have to worry about engine cooling levels. Unfortunately, most hire narrowboats, and even most privately owned boats, have only primitive methods of measuring these fluids. This can be quite unnerving to control freaks or Nervous Nellies who require precise knowledge of how many gallons or liters remain.

Fuel

The most baffling omission to many is the absence of a fuel gauge. One is usually told upon hiring a boat that it has a full tank, which should be sufficient for two weeks (or some other unit) of cruising. Upon further questioning, you might be told to refuel at a marina in the extremely unlikely event of running low, but of course you have no way of knowing if you do run low. The fuel tank (or tanks) is probably at the rear of the boat (although no two narrowboats have the same layout) near the engine and you could perhaps plumb the depth of the liquid or knock on the tanks, but realistically this isn’t practical. Many (but not all) private boat owners install a float gauge or fuel level sight tube to measure fuel.

Oil

Engine oil is the easiest thing to check because there’s always a dipstick that you should check daily. There’s probably also an low engine oil idiot light or tell tale that on the control panel will warn you of probably catastrophically low oil levels.

Propane

Your boat will almost certainly also be equipped with two or more propane tanks for the gas range (or cooker, stove and/or oven) and as with the fuel, you’re assured you will have enough for your trip. However, you might find when boiling water that it’s taking forever, which probably means one of the gas bottles is nearly empty. Switching from the empty to the new bottle should be relatively simple and will probably involve no more than turning a level or knobs, but your boat hire will explain the specifics. It’s extremely, extremely unlikely that you’ll ever need to install new gas bottles. The only way to determine how much gas is in a bottle is to pick them up and judge in one hand what you think is a full tank against a suspect tank in the other hand. I don’t recommend doing this.

Water

The water tank, which also is usually at the front, also usually has no gauge, although private owners often retrofit one. Tanks typically hold 100 or more gallons and on a two week cruise with four people would probably need to be replenished several times. Of course there’s no way of knowing you’ve run out of water until you’re standing in the shower with a head full of lather and suddenly the water stops. Some people claim they can judge water levels by how the boat sits in the water, but I doubt it would work for me. You wouldn’t know if it were water, fuel or sewage levels causing the boat to sit high or low.

Filling the water tank, by the way, is a two-person job. One person remains in the boat with the water supply tube emptying into the tank while the other controls the tap at the water point. With two people you should be able to avoid overfilling the tank and the well deck.

Coolant

As mentioned earlier, you might be told to check the engine coolant level. This depends on whether the engine is cooled by drawing canal water over the engine, meaning an inexhaustible supply, or whether the boat is equipped with tanks filled with coolant. Those tanks are usually flush with the hull to dissipate heat into the canal. Checking the coolant level on engines with cooling tanks is pretty straightforward and you’ll be taught the procedure at the boat hire.

Sewage

The most important fluid to monitor is the sewage because … sewage. For a mid-week or week long break, you’ll probably be told not to worry about filling up the sewage tanks, but if you’re on a boat where everyone saw the Moon landing live, ask about the procedure for pumping the tank(s). It’s unlikely you’ll be given a pump out card—like a debit card you can use to self operate a sewage pump out at a marina. (Pump out cards are available to purchase at the Canal & River Trust.) This is because the boat hire really doesn’t want you pumping out the tanks yourself. More likely you’ll be told to stop at a marina and pay to have the tanks pumped. If you do have to pay at a marina for a sewage pump out or refueling be sure to keep the receipts because your boat hire may reimburse you. Some boat hires have multiple locations on a canal so whenever possible use your hire company for pump out.

Unfortunately the only way to determine the sewage level is to look into the tank, which is directly under the toilet, while flushing. The tank will probably look empty until suddenly it’s very visibly full. When this happens, start looking for a marina and frequent pubs or canal authority restrooms. In fact I recommend using “land-based” facilities whenever possible.

Showers and sinks, incidentally, drain directly into the canal and so don’t contribute to sewage levels.