I have slide a wet waterski thru that space a few times, and have had no problems.

 

The only concern about using the TCH's 12-V battery to jump start another vehicle is that it's an absorptive glass mat-type of battery, and these batteries can be damaged by having to supply high cranking amps. They aren't intended for rapid discharge or rapid charge. They can withstand many complete charge/discharge cycles, however, which is why they are used in the TCH.

Stan