If the motor is the only thing on the cranking battery, there is no current draw unless the key is turned on. If there are other devices on it such as a radio that uses a constant voltage to retain memory settings, then there will be a drain on the battery.
2015 Seaark 1872 MV CC Etec-90
Helix 12 CHIRP SI, HB 1199, MinnKota Riptide ST80/i-pilot Link, Bob's Hydraulic
Bitter Gun Owner