The dogs what ya call its of search engines is...
5, 4, 3, 2, 1 GOOGLE click here
Use specific words to what you are wishing to look for. Using commom words will be omitted from the serach or they will be used and you'll have many unwanted sites because of these common words.
"Yeah i'm looking for ummmm submarimes, the nuclear type" - You'll get no where with this search query.
Nuclear Submarine - reveals thousands of pages. If you use more specific words like the name of a submarine you'll not only get pages with nuclear subs but also a specific sub itself.
Their Keywords as they are known.
Use as a few of words as possible and the words you use have to be specific to your query.
...However you can always get lucky.