http://www.partyideasforyou.com/fun-date-ideas-seattle/
What’s a fun, unique date idea for Seattle?
You can rent a boat (rowboat or canoe) from the University of Washington Waterfront Activity Center for about 7.50 an hour (non-student). It is a surprisingly low-key-romantic to row around under 520 amidst the lily pads, turtles, birds, etc.
http://depts.washington.edu/ima/IMA_wac.php
They are closed until February, so if you are planning a date for soon, you may need a plan B. I would definitely add this to your repertoire for another day, though
Plan B options:
Go ice-skating at Seattle Center
Take a ferry ride to Bainbridge Island
The Melting Pot is a fondue restaurant that is a meal experience unlike any other. The food is soooo yummy, and it is FUN to eat. (some of it is prepared table-side) The four course meal includes cheese fondue, salad, your main entree fondue (shrimp, chicken, steak, pork cooked by you in your fondue broth) and CHOCOLATE FONDUE! The four course meal is spendy, somewhere around 100 for two, so if you are short on money, it is also a fun experience to just go for chocolate fondue for dessert.
The melting pot is definitely fun, definitely unique, and definitely yummy:
http://www.meltingpot.com/
Enjoy your Seattle Date!
Italian Country Home And Kitchen- Seattle Area Italian Antique Furnishing Store