THere is two parts, one on the water, ie lk union as mentioned. Mostly BIGGER sailboats, and power boats. The indoor is at Qwest field. Smaller PB's, some bigger pbs, few sailboats and LOTS of venders with items for your boat and you. Some have stuff for sale, others such as manufactures will not have stuff for sale. ALA mustang is there with just about every PFD or equal they sell for show. but can get you in touch with a vender that sells the product.
Indoor show will also have some brokers with listed boats, pics etc. Mostly new boats at lake union and in the Qwest auditorium.
DO a day or two depending upon what you are looking for. 6-8 hrs minimum for qwest, 3-5 hrs for lk union depending upon the what and how fast you can look for it you are at shows like this.
In the past, order you tickets online, and you got a free yr subscription to a magazine, I think I have 3-5 yrs worth of sailing world coming to my door, along with a discount. A multiday pass is also availible, with IIRC bus/shuttle service to and from the two venues which are about 3 miles apart.
She drives me boat,
I drives me dinghy!