karaka maoa
1. (noun) person who can't swim - figurative term likening a non-swimmer to a mature karaka berry that sinks in water.
He karanga mate te hari i te karaka maoa ki te hī i runga waka, kāore nei ōna hākete whakaora (HJ 2012:20). / Taking a non-swimmer fishing on a vessel without her life-jacket is asking for trouble.