I would say you are on the right track.
If you want something to share with the boat, I would second OGs stereo and speakers. I love listening to music
and my hubby installed a great stereo that I can plug
my iPod into for my birthday. I'm not sure but I think I am getting new/better speakers for Christmas.
If not for the boat too, a gift certificate to a spa for a massage/facial/manicure (you name it) is always fun. Tickets to special events
, concerts, plays, etc. are also fun and extends the magic of Christmas a bit for both of you. Tickets/reservations for a special weekend get away for the two of you might be an idea.
What does your wife like to do?