What temp and how long do you smoke it for???
Semper Fi
Temperature is not something to take lightly. There are some pretty nasty illnesses you can spread if not done properly. To prevent botulism, etc., the thickest part of the fish should reach a temp of 160 degrees for at least 30 minutes. Your smoker will probably need to reach 200-225 degrees to get the thickest meat hot enough. You should also bring the fish gradually up to this temp, it may take 3-5 hours + to get there. If it gets too hot too quick you get a curd that forms. After the fish is done, and to prevent bacterial germination and endospores, refrigerate it at 38 degrees or colder (freezing will actually kill harmful bacteria that may have survived the curing and smoking process.)
It is also recommended that you rinse the fish and dry it AFTER brining it, and before putting it in the smoker. Rinsing will remove salt tolerant bacteria that survived the brine.
Here is an article by the University of Wisconsin that has great info on fish preparation, brining, smoking, as well as food safety.
http://www.foodsafety.wisc.edu/assets/pdf_Files/smokingyourcatch.pdf
A couple other notes: I scrape off all the slime on the skin prior too brining, and if I have time, will even scale the fish. Sometimes scales will accidentally end up on the meat. After the fish is brined, they are easy to spot and you can peel them off at that point. Great smoked fish starts early in the process, like right after you catch the fish. Bleed it, gut it and remove the gills, as those are areas where bacteria grows. Also make sure it's iced properly while on the boat, and kept refrigerated when you get home. The better the quality of the fish going into the smoker, the better the quality coming out of the smoker!!
I also use a dry brine and have yet to have someone turn down my smoked salmon. On more than one occasion I've been told it's the best smoked salmon/steelhead they've ever had.
Happy smoking!