Electrical issues

1962 arkanas traveler 16ft ski

1962 arkanas traveler 16ft ski/bass rig ..the last time i had this thing out . the problem started with no 12 volt from the on board generator . it wouldn't throw a charge back into the battery so i ended up leaving the rig on the water over night . so i could go recharge the battery . then the next day i got it going then almost didn't make it to the loading dock . then it died and never would restart like the amp's dropped to 0 . would this be a voltage regulator issue or generator or both

Pretty Hard to Tell........

Pretty Hard to Tell........

You've provided Absolutely No Information on the Powerplant......

A battery will start a engine.

A battery will start a engine. The alternator runs the engine once it is started. Sounds to me like the battery is low on water or has a bad cell. Another thing to check is a ground in the system draining the power. Turn everything off on the boat. Then hook up the battery. Did you see a spark? You have a drain on the battery.
One other thing to check. How about your connections. A bad or loose connection can give voltage but no amps or current. For instance a number 10 wire with one strand or two connected and the rest broken will do what I said above.
A poor battery connect will do it also.