lapworth here is
a running thread about legal lights. you might want to read it.
as for the flash light looking running lights for dingy's yes they might work, but only when under power.
there is a lot of misstatements here on lights, alot of people argue the USCG certified lights are the only ones legal. that is not true, it just means that the USCG has looked at and tested them and found them to be bright enough ( and proper viewable angles ) . there are other lights that are bright enough but the CG has not tested em. if i where to strap a 250 watt halogen to my mast as a steaming light, and it had the right viewable angles it would be legal even thou the CG has not tested it.
the catch comes in when you use a light that is not certified and something happens. the other person may try to blame it on your lights, you are then behind the 8 ball and need to prove the lights you used where bright enough
as for the electric end trying to run a 12 volt bulb on 9 volts would probably barely light the bulb.
if you dont want to spend as much you could build your own switch panel for around 20 bucks to control the running lights. as you only need 3 switches, running, steaming and anchor. if you dont have a motor you dont need the steaming, and if you dont have an anchor you dont need the anchor light. but i would not want to stop all the extra possible use i could get out of the boat by not having the extra lights. you are a short sail to annapolis, you might someday want to go up and anchor for the night for a romantic dinner. with the wife if you have one.