Plenty of experienced people on here have said that all you need on the front of your boat is a standard car fog light type lamp, mounted so that it points up towards the tunnel roof about a boats length in front of you, plus all the internal lights on.
At the rear leaving the rear doors open with the interior lights on will provide more than adequate light for you to see, and be seen from from behind. If you want something a bit more "personal" for you to see a bit more what is approaching you, then a small torch headlight is more than adequate.
If you wish to boat at night then the front "tunnel" light dropped downwards to fairly close to the front of the boat will be more than adequate. Anything more than this is both over complicating the matter plus potentially making you a nuisance by blinding boats coming towards you.
Keeping a good torch close to hand in a tunnel is also useful if your main lights fail for some reason.