My longest kayak is 15' and with a short bed on my truck it will stick out 9.5' past my tail lights; 5 of those feet past my bed extender. So even with lights on the extender I always kept one eye on the rear view mirror because there is still quite a bit of kayak overhang. I decided to build a setup which placed some lights at the end of the kayak and, as best as I understand it, exceeds the requirements of the Transportation Code Sec. 547.382.

I used 3/4" PVC, some electrical conduit fittings, LED lights, and flat black paint to build the light rig. All of my kayaks have rudders so I utilized the rudder mount to affix the rear portion of the rig after removing the rudder and cables. Since my longest kayak overhangs the bed extender by 5 feet I made the PVC frame just over 5 feet in length so that the strap securing my kayak to bed extender also holds down the light rig. The rear LED's are one of the smallest, red, 3-wire lights on the market which allow for brake and turn signals. I then used small, round, red and amber marker lights on the side. The PVC and conduit fittings let me cleanly wire everything within the PVC, except for the 8 foot jacket cable running to my truck's trailer lights plug.

Pics

Very nice. I may need to step up my game . Do you recall where you bought your light kit? I can easily mount something like that to my Hobie Universal Mounting plate.

Nice, I may need to do the same. I like to live bright and early and I am always scared of getting rear ended. Looked at maybe tying chem lights but rather have a setup like this.

This was more or less custom, as there was no light kit. Took me awhile to find a thin enough 3-wire, red, LED tail/stop/turn which suited what I was looking for. All in all I spent about $160 bucks on this setup. It could easily be done cheaper, but I built a clean look in my head which cost me to produce in real life, lol. Here's a rough breakdown of the costs.

Very clean rig.

I use a harbor freight bed extender with 4 prong tow lights attached below the T. I just zip tied the extra wire on the bottom. I have two red flags at each end of the T. Works really good, I loan it to a couple friends who've used it for 4 hour trips in tahoes with the back hatch strapped down lol

I did that as well with my bed extender. However, I still had 5 feet of kayak extending beyond the bed extender, so even with lights mounted on the bed extender I never felt at ease (still don't really).