Unlike on the land, where creatives can create a suite of fountains to dance and sway on command, incorporating a even simple water features such as a small fountain or a waterfall aboard a yacht brings with it many challenges to consider.
Because a yacht is designed to move through water, the opportunity to easily defy the laws of physics is lost. 'The moment you start rocking the boat,' says designer Evan K. Marshall, 'everything is thrown off.'
Problems with pools
Historically, the biggest consideration was how to manage water on the boat.
The movement of the boat itself creates a wave momentum in on-board pools that can become difficult to contain, even in the calmest of cruising conditions.
For this reason, the easiest solution was to use the pool only when the yacht was docked or at anchor, with all guests ordered out so that the pool could be emptied or drained to half capacity before the yacht got underway. While this remains a common practice, most pools are now also designed with deep surrounding sumps that capture wayward water and return it via a circulator pump and/or a holding tank that stores the warm water between uses.
Today the issue is not only about the 'wow' factor, but about incorporating the amenities an owner might enjoy on land into his yacht.
'When a boat grows [in length], the owner wants a bigger pool,' says Frank Laupman of Omega Architects. 'The pool is never big enough, especially for swimmers. We would like to make a 10 metre pool, but most of the time you can only do one of seven to eight metres.'
The typical solution is to create an infinity pool with a swim-against current feature.
Location is critical a large pool on an upper deck creates a weight issue that can interfere with the boat's stability and centre of gravity. For this reason most pools are placed on a lower deck near the stern. However, here you must consider the shape of the hull. While an owner might request a depth of around five feet, a fast semi-displacement hull, for example, would mandate that the depth stay in the three to four foot range.
The bigger the pool, the more water it will require, which adds weight to the vessel, and thus becomes a factor for the engines.
'We are careful with cutting-edge designs,' says Laupman, whose firm is currently working on a 73m boat for which a large pool is an important feature.
He agrees that there are more considerations than meet the eye. 'Most designers have to determine whether the pool should be located on the aft deck so that it is indoor/outdoor, or covered on the lower deck so guests can jump from the platform into the water. Then it becomes how to combine this design with saunas, gyms, seating areas, side hatches and whatever else might be required for the beach club.'
On the 73m project_ Omega, _the beach club floor was designed to be flush with the hatch that extends at the stern. The pool water is on the same level as the floor, which required some tricks with height due to the boat's shallow draft.
'You can only do this with a big boat, such as a Lürssen or CRN. Most of the time it is not possible; you need to climb three steps to reach the swim platform, which compromises the indoor/outdoor relationship. It's not really state-of-the-art work,' Laupman says, 'but you must do your homework.'
Interior water features
Designer Pascale Reymond of Reymond Langton Design likes to make a water feature an interior focal point, combining water movement with carved stone art pieces or contemporary ornamental glass, coupled with dynamic lighting, reflective surfaces and textures.
'Not only do waterjets or waterfalls add entertainment,' she says, 'moving water can mask any unnatural sounds to maintain a sense of tranquillity.'
In each of their foyer waterfall projects aboard large yachts, Reymond Langton have carefully engineered their designs to ensure the water flows smoothly in the intended direction.
This is an important consideration, confirms Jonathan Quinn Barnett, who has designed several interior waterfalls unfortunately for use aboard yachts too private to be published.
'Water doesn't always behave the way you want it to,' he says. 'It can take on a life of its own.'
Barnett advises consulting with an engineering group early on if you envision a specific water feature to ensure that the desired effect can be achieved.
'[An interior waterfall] is hardly going to be like standing next to a natural waterfall,' he points out. 'If you don't get that effect, is it worth doing?'
In 1994, Barnett created a 7m waterfall aboard a 73m vessel that fell the length of three decks.
'I used Plexiglas shields and angled the water back to minimize the splashing. By adding subtle texture to the wall,' he details, 'you can put some life back into the water as it falls vertically because it's falling down an uneven surface. Adding light creates a greater visual effect.
'With an interior waterfall, it is critical that you pitch the surface ever so slightly at the vertical,' he advises.
When the water is angled back at two degrees, it will attach itself to the surface and stay there. The water falls to a catch basin and returns to the top via a circulator pump.
On a 91m yacht, Barnett designed a bathtub that filled from a waterfall eight feet above.
'I incorporated LED lights recessed into the marble that illuminated the water as it cascaded down the surface,' he says. 'The marble also needed to be heated the same system as under-floor heating so that the water did not get chilled as it travelled from the ceiling.'
Oceano pushing boundaries
No builder has been more forward thinking in its 60m+ design concepts than Oceanco, who has assembled a consultative set of designers around the globe to provide intriguing designs, most of which exhibit water features that elicit a 'wow'.
The 87.5m Waterfall concept does just that. Envisioned by Andy Moore of Moore Yacht Design, the design has two versions: one with a large pool and the second with a smaller pool to allow for more lounging areas. Central to the design are waterfalls intended to mimic the 'unadulterated power and splendour of natural waterfalls'. On the version with the larger pool, the waterfall appears to originate from within the main superstructure and fall into the forward end of the pool.
'Implementing the design so that the function supports the aesthetics is a complex matter,' says Moore. To keep the water off the deck, the main body is aimed into a large, deep drop-off. From there the volume is reduced as it cascades under a bridge and through the aft superstructure. Each water level is designed so that the cascades will not fall onto the deck, steps or transom when the yacht moves.
'One cubic metre of water weighs a ton, so there are certainly some important stability considerations to take into account at the planning stage of any significant water feature aboard a yacht,' notes Moore. 'For this design, I have worked closely with the naval architecture and design department at Oceanco, which currently have engineering studies underway.'
While the likes of Jon Bannenberg and Tim Heywood have successfully executed designs with water that flowed down between masts or pools that filled with waterfalls, some scepticism remains.
'When you're at sea,' says Barnett, 'playing with too much water on deck runs the risk of being gimmicky. You have to be extremely careful to ensure you achieve the desired effect especially for the cost, maintenance and logistics required to run water down, through or under decks.'
But exploration and development into the area of on-board water features remains strong.
'We are exploring a design where water originates at the top deck and falls to the stern and into the water,' says Stefan van Cleef of technology specialist van Berge Henegouwen. In this design, the water maintains its course even when there is movement.
'The higher it gets, the more different the route of the water droplets,' says van Cleef, 'but so far the biggest problem has been to curb the sound when such a feature is placed in the interior. We are exploring other areas and ways around it.'
Yacht design often takes its inspiration from other industries, and with water features it only makes sense that we explore what has been achieved in the cruise ship sector. The 360m Oasis of the Seas features a water-based theatrical space at the boat's stern with a deep pool and nozzles capable of shooting streams of water up to 20 metres into the air.
Designer Martin Francis acted as a consultant on the Oasis project and is well versed in both worlds of private yachts and cruise ships.
'Cruise ships don't move much relative to yachts, so incorporating a fountain can be pretty straightforward. It depends on how big the fountain is and, provided the wind direction, water can be pumped up.'
California-based Fluidity Design Consultants were brought in to advise on this particular aspect of Oasis's water feature.
'With a ship's motion, there is no way to guarantee a level,' says Fluidity's vice president Tom Yankelitis, 'so this eliminated certain types of effects we could achieve. When you're pumping water through a nozzle, you're only relying on pressure so it doesn't matter what angle the boat is at because the water will perform at a relatively consistent manner in that device.'
Fluidity Design presented a range of nozzles that were more resistant to ship motion and wind that could turn on or off, shoot water up in the air and in an arc across the pool. Nozzles incorporated into a bridge above the pool allowed for a rain effect.
'Even with these particular nozzles, we still had to do things in the space to mitigate wind and the wave action in the pool,' says Yankelitis.
During the design process, engineers had to reconfigure a two- to three-metre wide lift down the centre of the pool to be strengthened for lateral motion to attenuate the wave action and lessen the lateral force.
Studies also determined that the space's location at the aft end of the ship would have wind blowing from the rear back in, so sails were devised to protect the water effects. In the end, the architects ended up conceding that the first four rows of spectators might be splashed upon.
Will we soon see choreographed fountains swaying on the stern?
'Anything is possible with money and a bulldozer,' says Barnett. Beware, however, as even aboard Oasis of the Seas one of the challenges was scaling down the power consumption required by the spray nozzles. 'A modest fountain with a dozen vertical nozzles spraying six feet high would require about four times the power of a 20 by 15 foot unheated swimming pool,' says Yankelitis.
If you can fit a pool big enough, Martin Francis has designed and pioneered a system of wave attenuation implemented aboard the 80m _Golden Odyssey _to combat that age-old issue.
'The system is designed to take the momentum out of the wave,' Francis explains. Based on the interring anti-heeling system of interconnecting water tanks used to stabilize ships, water flows from one tank to another in a controlled way designed to dampen roll. The wave is captured at the pool's edge in a holding tank and released back into the pool as the ship rolls. This takes the top off the wave and is 'very effective,' says Francis.
Incorporating a water feature isn't a complex problem, states Barnett. 'Once you work through the logistics of it, you can get some fantastic effects. There may be some compromises to be made, however.'
Eduard Gray of Gray Yacht Design is ready to push that envelope.
'As a designer I work with engineers who try to interpret my design into real-world solutions,' he says. 'This way, I am allowed a degree of freedom for innovative thinking before being brought back to earth with the constraints of regulations and physical limitations.'
His latest design, the 100m Sovereign, features an infinity pool with a glass-topped helicopter landing pad. Regulations aside, how do guests disembark from the aircraft with out having to swim? But that is what engineers are for.
Originally published: MegaYachts volume 14: Concept Design Construction (2013)