Think Bubbles

[Trophy885]

Dear All,
what could I mean??? Excess of Aero? Or perhaps the moonwalkers chimpanzee????
No, I'm talking about my usual bain, My '8!!
Tried unsuccessfully to start it last night, (cold again!!) inserted the key in the ignition, span emgine over, fired, stopped, and then a bubbling noise from the rear..
Could anyone tell me what, if anything might be under the battery?? Possibly getting water logged, maybe vacuum pump for cent locking??
Many thanks Guys'n'Gals
Best Regards,
Steve