PHP Warning: Use of undefined constant VBA_SCRIPT - assumed 'VBA_SCRIPT' (this will throw an Error in a future version of PHP) in ..../includes/functions_navigation.php(802) : eval()'d code on line 1 Current Capacity
Yes you can.
You can run any 12V accessory off it but the time before going flat would vary.
The sounder and GPS should last a fair while.
At max. full load (5.4A) it will only last less then 4 hrs.
I just had a gander at the specs of these.
The GPS draws 14W which is close enough to an amp.
The sounder draws either 1 or .5A (must be different transducer types)
So if they're both left on and you have the super-duper transducer then the battery will last about 10hrs