Question

what did the mayflower passengers drink rather than drink the unsanitary water

Answer 1

The answer is beer.

The Mayflower passengers drank beer rather than unsanitary water.

The Mayflower was an old ship that was intended to carry cargo and not passengers from place to place. Thus, it lacked the basic conveniences that any passenger would require in a ship. However, when it had to undertake a voyage with Pilgrims to New England, there was an acute shortage of food and water. This is why the passengers drank beer rather than opting for unsanitary water.

Answer 2

The pilgrims who went to Plymouth Rock on the Mayflower drank beer in the form of ale instead of the unsanitary water.

They could fall sick by drinking plain water which was unclean and could harbour bacteria. So it was more safe to drink beer on the voyage. Beer has a low pH of around pH 4 - 5. It does not harbour pathogenic bacteria. Another reason was that ale provided them some amount of the calories needed for the journey.