A futuristic new concept that's inspired by whale tails could change the way we travel through water.
At the moment, almost all vessels capable of travelling great distances do so with the help of enormous propellers that provide the driving force.
However, the Seataci, a $100million (?77million) luxury yacht envisioned by Montreal-based engineer Charles Bombardier, is designed to travel with the help of a wave motion - just like the way whales do.

In his column for Wired, Bombardier explained that the Seataci would use an eco-friendly system that could be more efficient than traditional systems and allow the vessel to travel through shallow waters and with minimal noise.
Like all yachts, the Seataci has a main hull, where the bulk of the ship's features will reside.

Bombardier suggests that the submerged portion could feature panoramic windows, providing an insight into aquatic life.
The space, in turn, could be used for an observation gallery or a dining room.
Seataci's upper decks might feature a tropical garden surrounding its swimming pools and offer space to land its passenger drones, which would shuttle guests on board.

Rather unusually, the yacht also features two engine pods that flank the vessel on each side, which are submerged using a water ballast system similar to those used on submarines.
These pods help to stabilise the yacht and propel it forward using waves created by 'an oscillating foil' that's designed to mimic the motion created by marine mammals such as whales and dolphins.
To reverse, the vessel needs to take in water from side gills and push it out from the front of the pods - just like a squid or octopus might do.
But the pods are more than just engines.
According to Bombardier, they will be accessible anytime and could provide an alternative view point for the vessel.
While the Seataci is just a concept at this stage, Bombardier told Forbes: 'Price is relative?it depends on many variables, but I think the initial budget to develop and build the first prototype would be around $100 million.'