Welllll ALLLRRIIGGHHT! Finally, after nearly a year and a half, I seem to have found the root of my starting problem on my 1979 Catalina 27's venerable Atomic 4. Jim Huhta and one other owner asked that I reply when I fixed this issue, so here goes. Symptom: The Atomic 4 would run fine out out of the slip and out into the channel. However, voltage would drop off rather quickly. Usually, after around 4 or more hours of sailing, the batteries would be hovering around 12.4 to 12.3 volts. If I started the engine at this point, it would turn over once, but if the engine did not catch the first time around, she would refuse to crank any more. The Ammeter would peg itself on discharge when the ignition was turned to START, but nothing would come from the starter - not even a click. Mysteriously, if left to sit for an hour or so, she would crank again and fire up beautifully. Action: So, I began replacing things - first new battery cables, then new batteries. No change, still sporadic starting problems. Bought Nigel Calder's book (should have done this soooner!) and changed out battery selector, added battery combiner, and bought new three stage charger. Still no luck. Installed negative battery bus and re-checked all ground wires for a leak. Nothing. Solution: Finally, in desparation, I began to figure it was the alternator and/or starter. Taking a reading off of the alternator still confirmed that I was getting 13.8 volts - adequate voltage. Hmm.... Look at the wiring, dummy. It appeared as though the voltage wasn't making it back to the battery. Culprit - two severely undersized and just plain old leads running back to the battery banks. UNBELIEVEABLE!!! I had never suspected that Catalina would allow such shoddy wiriing to be implemented! The leads going back to the battery bank were probably 12 guage wire, maybe 10. It is possible that the PO had rewired it and took his usual cheap route, so I can't totally blame the manufacturer. It is no wonder that the boat was behaving so poorly - the engine was feeding off of the batteries to provide spark to the spark plugs! This explained the failure to crank after just a little cranking, and the fact that an hour of rest would allow the batteries to crank again. Bought some 02 guage wire, new terminals with solid crimp and liquid electrical tape, and Voila - problem solved. What did I learn from all this? First off, consult Nigel Calder - and if you are having problems with a concept, such as bonding, grounding, or 12v in general, just read him until it makes sense. Second, never trust anything on the boat that you have not done yourself (and sometimes even then be skeptical 
). Lastly - never give up! In the mean time, I have learned how to sail my boat back into the dock without power, anchor without power, and generally sail without depending on the engine. As an added bonus, I now have a rock solid, bad ass, completely oversized grounding and wiring system on my boat that will probably outlast the rest of her. Hope this helps anyone else who is chasing the same or similar problems.
). Lastly - never give up! In the mean time, I have learned how to sail my boat back into the dock without power, anchor without power, and generally sail without depending on the engine. As an added bonus, I now have a rock solid, bad ass, completely oversized grounding and wiring system on my boat that will probably outlast the rest of her. Hope this helps anyone else who is chasing the same or similar problems.