You might have to wash the bilge out with a detergent or degreaser to remove the oily diesel.

In our ski boat years ago, we used to use Napisan, chuck a cup or two in with some fresh water and swish around for a day on the water. Then swab it out, although it should be safe to pump out of the bilge if you're offshore. Once you have the diesel out, spray in some vanilla and or vinegar, it usually takes another day or so of fresh air flow and you should be right.

felixdcat said..
Thank you for the tips guys, I will pass it to my mate!

Hey Felixdcat...I'm in a unit overlooking Mandurah and Halls Head and didn't see any spill, so must be all good!!!

For what it's worth.....

The diesel fuel will float on top of the bilge water. It's a really good idea NOT to get the boat rockin' and rollin' with that load on board as it will "smear" up the walls of the bilge and be a b***h to get out.

Often the bilge pump inlet hose is right on the bottom of the bilge ( as it should be) and therefore won't pump out the last of the diesel which was sitting on the top of the water. It never quite gets out of the end of the pump hose....just flows back in... smelly.

Suggest consider soaking up as much fuel as possible with bilge socks ( they repel water and will soak up oil and fuel oil) but they will become waterlogged if you put detergent in the bilge as this reduces the surface tension. The bilge socks are expensive but diesel smell is so difficult to get rid of you might consider it worth it..I've used cheap toilet rolls and disposable nappies and they work fairly well at a much lower cost but they are messy to use.

Absolutely agree with a citrus scented commercial detergent. Worked well for me. And vinegar. And vanilla!!!!!

As I had a wet bilge on my Salthouse 48 ( in-mast furling so rain water ingress was an issue) I used to, thereafter, put a bottle of SugarSoap / CR18 Bilge cleaner into the bilge every few months. This meant that I wasn't terrified of the de-watering bilge pump lobbing out dieselly-water in front of everyone ( EPA, Parks & Wildlife etc) at anchorage in the event of some fuel drips or oil accidentally finding it's way in the bilge.
My bilge, which absolutely stank of diesel ( major fuel leaks, diesel and oil, prior to purchase) when I first bought the yacht eventually became sweet smelling...well, OK-smelling anyway. I'm sure the continued regular use of bilge cleaner is worth it in the long run.

Just my experiences...hope they might be of some help.

Fair winds to all.