This is a popular day trip from anywhere on the west of the island, but for a really romantic experience, try booking an overnight stay at one of the three options at the area (I HIGHLY recommned the Innchanter, but there is also a hotel across the cove and a campsite right at the base of the trail) so that you can have the springs to yourself at high tide at night. It's an exhilarating and romantic experience!
We took one of the day boats up--a combined hot springs/whale-watching trip out of Tofino. No whales sighted (it was off season), but we did see several eagles and sea lions, along with the beautiful scenery of the coastline. On arrival, we stowed our gear at the Innchanter and took the hike through a beautiful and ancient rainforest on a path with planks carved perhaps by previous visitors. Some of them are interesting, and the hike itself is lovely.
There are bio-potties and changing areas at the top of the trail, along with a place to shower off. It wasn't terribly crowded, but groups did come and go as boats arrived and left. Some of the terrain can be a little rough. After hopping around on the rocks for awhile and enjoying the water, we hiked back down for dinner and a gorgeous sunset over the cove.
Around midnight, at high tide, we tendered back over to the pier and took the trail back up to the cove. Yes, you do have to be careful not to startle any bears that may be around, and wear good shoes because the planks can get slippery at night - but we didn't have any problems. When we got there, there was no one else around and we found a pool where the cold water from the ocean washed into the warm water from the springs, making an exhilarating hot-then-cold sensation for some "au naturel" bathing. The moon was the only light, and the stars were incredible.
Eventually we made our way back to the Innchanter, were we sat out on deck chairs and watched a meteor shower. We slept like babies, and the next morning (after a yummy breakfast), we caught a boat back to Tofino.