What's the longest English word you can make using only vowels?

The longest one I’m aware of is euouae, which has very little (or no?) use in current day language, but is listed in the Guinness book for longest vowel-only word.

When it comes to longest consecutive vowels – queueing is a favourite.

After a bit of research I turned up AA, EAU, IAO, OII, EUOUAE, OO, AIOUEA, AIEEE, IOUEA and UOIAUAI.

However, after checking the scrabble dictionary, the only one that is legit by scrabble is aa, which is a type of lava. Your best bet is not to find words that consist of all vowels, but to change your playing style to try to use more vowels in general, so that you don’t end up with all vowels on your board.

re the above, it’s called “rack management,” as described in Stefan Fatsis’ Word Freak

Without meaning to be chicken, there’s always the option of getting rid of your letters and skipping a turn. I’ve only done it once in all the years I’ve played scrabble, but what a fantastic feeling!

You might be interested in “vowel dumps.” There are lists all over the internet, such as http://www.cyberonic.com/~bigdoggy/vdumps.html. One of the many lists that really great scrabble players will take the time to memorize, and the rest of us just let go.