I will also put in a plug (!) for the 2-pin 12 volt plugs - we call them T-plugs as the pins are arranged in a "T" I have used them in my boats for over 20 years with no problem, - we even used them in our RVCP patrol boat in Melbourne, which was a 12 metre workboat permanently moored in the Yarra, with no corrosion to speak of. The pins are easy to clean with emery paper if there was any corrosion, and they have a large surface contact area to pass plenty of current without heating up. We were originally put onto them by the amateur radio group WICEN, whose operators we used to carry on board on the Red Cross Murray Marathon.
Richard.
p.s. Important point when considering spotlights - get one with the narrowest pencil beam that you can find - a broad beam at night results in a lot of light scatter and refraction back into your eyes, reducing its effectiveness.
R.