Although so close to home, I haven't explored Squamish too much via SUP. I usually visit Squamish to camp, hike, and occasionally climb. This summer I plan on paddling to one or more of the campsites along the Sea to Sky Marine Trail and will report back! I found that paddling in Howe Sound gets very windy and it's best to paddle in the morning or evening and be confident on your knowledge about tides and currents. If you're just starting out with the sport, I'd recommend one of the nearby lakes like Brohm, Cat, or Alice Lake.
To get this killer view of the Chief, my friend and I launched from the marina across from Howe Sound brewing. It's a short paddle north for the photo-op, then we turned around to explore more. On a separate visit, I paddled towards to the Squamish Estuary where I was surrounded by pink salmon making their way up to spawn. I wish I had a Go-Pro for that amazing yet smelly experience.