Ancient seafaring lore would have you believe that the following people will ensure a disastrous voyage:

People with red hair (although this can be neutralised if someone speaks to the red-head before they speak themselves)

A crewman carrying a black travelling bag (this represents the colour of the ocean depths and therefore death)

Flat-footed people (neutralise as per red-heads)

People who step aboard left foot first

Priests

People who wear the clothes of a dead sailor

People who say the word ‘drowned’ on board