Little could prepare the emigrants for life aboard an ocean vessel at sea. Regardless of the routines established by the passengers and crew they still had to deal with a number of unexpected and uncontrollable factors, such as seasickness, contagious diseases, poor diet, and piracy.

One of the greatest unknowns over which they had no control was the sea itself. Even when the weather cooperated and seas were fairly calm, the open, rolling sea was a new experience, and storms at sea could turn their new experience into a nightmarish one. Tales of the dangers of the sea were widespread among mariners and nonmariners alike; the Reverend Francis Higginson wrote of one "sore and terrible storme" when "the wind blew mightily, the rayne fell vehemently, the sea roared & the waves tossed us horribly; besides it was fearfull dark & the mariners... was afraid...