Subscribe | UPI Odd Newsletter Subscribe ELKHORN, Calif., Dec. 2 (UPI) -- A man kayaking in California ended up with a unique story when a massive sea otter jumped into the boat with him. John Koester was kayaking with his wife, Heather VanNes, to celebrate his birthday Monday in the Elkhorn Slough, near Watsonville, when they spotted a raft of sea otters in the distance. Advertisement The couple said they made sure to keep at least 50 feet away from the animals, but one of the curious otters quickly swam over to Koester and jumped onto his kayak. VanNes snapped a photo of the massive otter and posted it to Facebook. The couple estimated the creature was about the size of a German shepherd and weighed 80 to 85 pounds. They said the otter was a calm and friendly passenger. "He was just happy to lie there," VanNes told KTVU-TV. They said the otter eventually jumped off the kayak on its own and rejoined its comrades. Read More Lion cub plays with otter at Florida facility Rescuers arrange rare reunion between 2-day-old sea otter pup and mother Talented otter shows off juggling skills at British zoo