The last few times out with my boat I have charged the starting battery before I go out, sometimes the night before.   When i start my boat it turns over as normal and continues to do so every time I fire it up to move.  However, sometimes after 6/7 moves, I will go to turn the key and the motor makes no sound.  I will wait a few seconds, try again, sometimes I get a little sound that is sluggishly trying to start, sometimes nothing.  After I do this few times it will start.   I just don't know if it's something with my starter or if my battery doesn't have enough power to engage the starter.   Any thoughts?   The battery is maybe 3-4 years old.  Engine is a 2001 honda 4 stroke 50 hp.