Simplest thing to do is to create a directory ~/.vim and create a file within that called filetype.vim with the following contents:

Code:

" my filetype file
if exists("did_load_filetypes")
  finish
endif
augroup filetypedetect
  au! BufRead,BufNewFile *.ocn  setfiletype skill
  au! BufRead,BufNewFile *.ils  setfiletype skill
augroup END 

This will tell it to treat files with the suffix .ocn as SKILL code (which is what OCEAN is).

Regards,

Andrew.