Okay, first off I have to admit I had to look up the correct spelling for this word. It seems the British enjoy the use of the letter U a lot more than Americans, but either version is considered correct. Sometimes I think I should use the American style so I can refer to it as a 4 letter word. Anyway, I digress.
Mould is a nasty, nasty thing and it LOVES the boating environment. That's because it needs just a few ingredients to start having a party:
Temperature: The absolute most favourable temperature for mould growth is between 25 and 30 degrees Celsius (77 to 86 Fahrenheit). Yep, boating season temperatures
Water: Condensation, pooling water, humidity - these are the key to mould's heart. Yep, boating = water and humidity
Oxygen: It doesn't need much! Just a tiny bit keeps it going
Food: Mould can digest ANY organic matter, including foam. Apparently, foam is surprisingly tasty
When it comes to mattresses and foam, lack of circulation is another huge problem. Moisture gets trapped under your mattress, and before you know it mould is having a party.
So unsurprisingly, the boating environment can be very hospitable to mould, and vigilance is essential.
Check your mattress
If you haven't checked in while, take a moment to unzip the cover on your mattress and look for mould, especially on the bottom. If looks just like this (actual pictures from mattresses we have replaced):
Store your mattress carefully
Keep your mattress dry, and try to store it off the boat in winter or elevate as much as possible off the platform to allow air to circulate around it
Use moisture absorbing products
There are many moisture absorbing products on the market, many of which are designed with the boater in mind. Brands include Boatsorb, Sorbatech and Star bright. Make sure you deploy them in your berths during the winter months and keep your eye on them if you can - you may need to replace them half way through the winter.