Casual sailing near shore would be possible, though characters would first have to construct their own boat. Since Duplicity natives fear and avoid the ocean, boats are not available for rent or sale. Swimming is possible, though not without risk — being caught in an undertow and drowning, for example, or being ensnared by a tentacle from the deep. It would be safest to swim in shallow water or close to the side of the boat. Fishing is also possible. Some fish would be normal, others might be strange. For reference on potentially strange fish, you can assume they would be like those displayed in the aquarium.