Hi ;
If you are talking about making plastic look this way then you can do this . Sand your hull and deck pieces with 320 dry . Then brush it off .Go over it from bow to stern with a wire brush . Take a stiff natural fiber brush and clean off all the fuzz .Now coat it with a thin coat of dark brown and within minutes wipe the hull and decks off.
If you want the deck to reflect old aged teak then here's where it gets interesting: Take those pieces and do the same with a medium brown/dark grey mix. Wipe it off in a few minutes too. The dark colors will settle into the grooves your sanding and wire brushing created. Wait a day and then go over the whole thing except the decks with a medium brown wash. Then go over it with a dark brown final wash coat.
As to the decks, finish them with a medium grey wash OR if you want holystoned decks then use a mix of cream and light grey in a wash as well. Don't forget, all wipes go from stem to stern .
I hope this helps you .This is the formula I use on all wooden look vessels made of plastic.