How big is "the Seattle area"?
We did a trip with
Prince of Whales out of Victoria, BC last July.
It was great fun and we saw plenty of orcas. Seems there are several "resident pods" in the area (San Juan Islands, I think) and, as Paul Clapham said, the tour operators know where they're likely to be and when.
We saw plenty of orcas on our trip. A friend in Victoria we were visiting said a coworker of hers went the day before us (paying for 7 family members) and didn't see any. So it seems like it can be hit or miss.
I thought the ride on the Zodiac in choppy
water was worth the ticket price, even if we hadn't seen the whales!