Answer: deadcalm

AnswerCrossword Clue
DEADCALMSailor's concern
DEADCALM1989 Nicole Kidman film
DEADCALM1989 Neill-Kidman thriller
DEADCALMCause of a full stop for sailing ships
DEADCALMBad news for sailors
DEADCALM0 on the Beaufort scale