I have a question. I have a ford 460 with holley 750 dp. When I drop in water, turn key on, I can hear fuel pump pushing fuel to carb. Wait 5 seconds or so then I light her up......but she don't light. After approx. 5 to 10 attempts she fires. Runs great. Then the rest of the day she starts no problems. Is this because there is no choke or is there a choke??? Is there anything I can do to remedy this problem. It's a pain sitting in marina trying to get boat to fire Not to mention a bit embarrassing. Thanks for any input. 
So, are you pumping the throttle at all?
Mine takes 1-2 pumps when its cold (not having been run that day), and 1/2 a pump (more of a bump) if it has been run earlier.
Chokeless boats here, too, and electric fuel pump.
BTW, what Ignition system?
Dan'l