CORRECT CRAFT super air 230 2018 Owner's Manual page 240

Section 7
Take care when connecting or disconnecting a battery charger. Be
sure the charger is turned OFF and unplugged from power source
when you clip ON/OFF the connecting clamps.
Make sure you have a solid connection with the charging clamps.
Poor connections are common causes of electrical arcs and engine
problems. Follow instructions.
DO NOT make or break electrical circuits at the battery terminals;
a spark will occur when a live circuit is opened or made. Turn off
all components.
Use a voltmeter or hydrometer to check the battery charge
condition.
The battery cables should be removed from the battery when the
boat is placed in storage, on display or in transit. This will eliminate
the possibility of the engine accidentally starting without a supply of
cooling water and may damage the engine.
A
CORC212
+ = red positive (A)
- = black negative (not shown)
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