Not to be contrary, but I work part-time for a marina, so I've dealt with this a lot.
I'd advise you to go back to the DNR, and ask them for the proper procedure. If the clerk gives you a hard time, ask for her supervisor. Many times, the supervisor will come out, chastise the clerk, and give you the proper forms and instructions.
In VA, you have to do a title search, and then send certified letters to the last known owner. If they respond, great, but if no response in 15 days, the DNR sends a letter, and if no response, you get your title. Most other states I've dealt with HAVE a similar procedure, but it is a PAIN to get them to disclose this fact.
Always start out by being very nice, then become more and more firm, but still polite, asking for each person's supervisor until you get to someone who knows how to get this done legally. I've had to go to the branch manager more than once, and every time, she hands me the papers, and thanks me for my patience.
Hopefully, it will go well for you.
-TH