I've never been fishing at night.  I was wondering what other supplies are a good idea to take along. 

I'd also say be up on your self survival skills; if you go in the water at night you might be there a looong time otherwise.

Carry multiple lights and a whistle; the whistle is good for getting the attention of a drunk idiot in a powerboat who's not paying any attention and is about to run you over. 

Other than the stuff you need during the day I'd say a head lamp is a must, and a bright light for your stern.  I use a regular boat anchor light (stern) on a 36" pole, you can buy one from West Marine and modify it to zip tie it to your crate.  Other kayakers have been known to joke on me for my super bright light but every boater I come in contact with tells me they wish all kayakers had a light like that so they could see em.  I used the 'flashlight' type for a year or so and then got tired of it not working or having to replace the batteries every two trips.  Get a 12 volt and a charger.    You can get one like this at Batteries Plus:

Other than that you need a map to the HRBT but we won't be talking about that online much longer .  It's dead there now but all we need is a tiny bit of cool weather........

I can confirm that orlowskr's light is super bright.  I also have the Scotty light and am getting ready right now to go buy a different one that I feel safe with.  The Scotty just doesn't put out enough light for me.