The cabin chairs used in the Spindrift are the same design as those used in the cabin of the spaceship seen in the original "Planet of the Apes" (1968), also in production at 20th Century-Fox in the summer of 1967.
In the first several episodes of the series, during daylight hours at the spaceship campsite, the sound of tropical birds can be heard. This was an obvious mistake on the part of the sound editor - on seeing the abundant foliage around the campsite, he probably assumed that the ship had crashed in a jungle setting (as per the series it was established as a giant city park). This sound track was removed in later first season episodes.