Modern superyachts can cost tens of millions of dollars, and the wealthy people who have them custom-made are prone to coming up with some outrageous requests.

This summer, yachting journalists Frances and Michael Howorth asked some of the top names in the industry to answer the question:

"What is the weirdest/craziest request you have had from a client during the building of his yacht?"

Here are a few of the best answers, extracted with permission from the article "You Sail Me Crazy!," published by the Monaco Yacht Show.

Rodney Martin, Managing Director Fitzroy Yachts:

"Owner’s rep came on board late in the build, thought that the saloon cabin wouldn't be tall enough to accommodate the Owners cowboy hat, and asked us for a variation to raise the saloon roof by 100mm. The variation came back at several hundred thousand - and the next day it was approved by the owner!"

Luca Bassan Antivari, President of Wally:

"I recall one occasion that clashes somewhat with the laws of physics where an owner asked for at least two metres of cabin headroom using only one and half metres of height! Another wanted a lift capable of going up to the top of the mast with his guests so they could drink and watch the sun set. We managed to persuade him that a chopper would do it much more efficiently and safely.

"My favourite however, was the guest who wanted his 50 metre yacht to have a glass bottom so that he did not need to get wet while watching the fish. He wanted it to be a sort of sailing snorkeling, or snorkeling while couch potatoing experience."

Vincenzo Poerio, CEO Benetti Yachts:

"The Owner of Ambrosia III had a passion for astronomy and wanted a planetarium inside the sky lounge. He wanted it to simulate a real night view of the stars, planets and constellations. It had to be able to change and rotate (and open) according to the real boat position in terms of latitude and longitude. We did it of course, gaining at the same time a deep knowledge in complex astronomy!"

Rupert Mann, Rainsford Mann Design Ltd.:

"Over the years many a request has been far reaching and challenging but usually mixed with modicum of sanity but the bar was raised when a client requested we incorporate a mini version of the owners’ suite for Bart, their pet monkey!

"The “Simeon Suite” as it became known, was even to have its own galley to enable Bart’s favourite snacks to be prepared. Unfortunately due to international quarantine laws this idea never really got off the ground further than the paper it was designed on!"

For more crazy requests, read the full article here.