The trail is well maintained and receives heavy use year round. Many trails go through the park, and there are several different trails going up to Goose Rock itself. Deception Pass is named because of the incredible currents and eddies that pass under the Deception Pass bridge. From that Wikipedia link:
Deception Pass is a dramatic seascape where the tidal flow and whirlpools beneath the twin bridges connecting Fidalgo Island to Whidbey Island move quickly. During low tides, the swift current can lead to standing waves, large whirlpools, and roiling eddies. This swift current phenomenon can be viewed from the twin bridges' pedestrian walkways or from the trail leading below the larger south bridge from the parking lot on the Whidbey Island side. Boats can be seen waiting on either side of the pass for the current to stop or change direction before going through. Thrill-seeking kayakers go there during large tide changes to surf the standing waves and brave the class 2 and 3 rapid conditions.We hiked to the top of Goose Rock and found it was breezy and a little too early to stop for lunch, so we hiked back down to the beach. We saw these whirlpools that had picked up in intensity from our earlier view.
(News flash: We thought we heard some shouts and saw an orange Coast Guard helicopter overhead several times. It turns out they were rescuing two kayakers who overturned in that turbulent water. Story on the Whidbey News Times here.)