Spooky that you should ask this question.
I was going to put together a topic detailing with photo's and videos (youtube based) in the new year, so that if anyone wanted to weather their models, all they would need to do is follow my photo/text examples.
The rust in that boat will not be difficult to achieve, just very time consuming - you will need sea salt, rock salt, salt flakes to begin with. Watch the videos about using salt or hairspray, ordinary table/cooking salt does not work. Also your paint medium needs to be acrylics not enamels and preferably of AK, MIG, AMMO, ModelColor, Tamiya extraction. There are a few others but acrylics from diy/Halfords shops will not work, they have to be modelling acrylics.
If you check out Modelcolor and AK Interactive websites, they also do rust paints making it even easier. Not only rust, but diesel oil, petrol, rain stains, moss, lichen, mud, thick rust, snow, the amount of paints just for 'weathering' a model is vast, I have 20 different pots of weathering paints besides my standard model paints.