Boating New Zealand – April 2018

90 Boating New Zealand

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eaking oil lands up in the boat’s bilge. Any water that

fnds its way into the boat through worn drive-shaft

seals or rudder bearings also eventually ends up in the

bilge, with the automatic bilge pump taking care of

the messy mix.

Which means that unless the boat owner is extremely

diligent, a typical boat is prone to occasionally pumping a mix

of dirty water and some oil out the side. Tis may be invisible

on outboard-powered boats since the oil seeps away at the same

rate as it drips out, but for older diesel-powered launches and

yachts the impact of the bilge pump suddenly turning on can be

very visible.

Internationally, 15 parts per million is the maximum

amount of oil permitted to be pumped overboard. Tis level is

virtually invisible – so if your bilge water leaves a sheen of oil on

the surface, you’re breaking the law.

In New Zealand, enforcement of oil pollution regulations

falls to Maritime NZ and the regional harbourmasters, and

recent fnes in the tens of thousands of dollars for commercial

violations show how seriously they take this. Until now

recreational users were more likely to be warned than fned, but

regulators are getting tougher and fnes are being levied more

and more often.

At the very least, every boat owner should check the bilge at

the start and end of every trip. Checking after the engine has

shut down ensures any problems can be sorted before the next

trip out. But it is also important to check just before you head

out, because although the engine may seem fne immediately

after being turned of, a new leak could develop as it cools down.

Obviously, your frst task is to deal with the source of the

oil – apart from the mess, there is a risk of damage to the

engine should the oil level drop below minimum operating

requirements.

Second, you have to deal with the oil that has leaked.

Most diesel engines – while powerful, fuel-efcient plants

• also drip a small amount of oil. The older the engine and
  gearbox, the greater the chance of leaking seals.

Well-oiled

with NORMAN HOLTZHAUSEN

DIYBOATING