Hurricane - cooking recipe

Ingredients

1/2 ounce white rum
1/2 ounce dark rum (or gold)
1/2 ounce gin
1/2 ounce Amaretto
1/2 ounce pineapple juice
1/2 ounce orange juice (more)
1/2 ounce grapefruit juice (more)
grenadine, to taste
1 slice orange

Preparation

Put ice in a Hurricane glass or a really tall glass.
Then add the white rum, dark rum and gin.
Add an equal quantity of pineapple juice, orange juice and grapefruit juice. (what I do is that I use equal quantity of orange and grapefruit juice, and a little bit of pineapple juice, all unsweetened).
Then you can put the amaretto on top.
Add grenadine. (I don't).
Garnish with a slice of orange.