(Bloomberg) — Lounging in the Caribbean aboard a beautiful,100-foot superyacht sounds pretty great, but it might be hard torelax when you have a hefty engine repair bill to pay and crewpayroll paperwork to review. The annual cost of operating a180-foot vessel is $4.75 million, or about 10% of the yacht'soriginal cost. With high maintenance costs in mind,ultra-high-net-worth individuals looking to explore the high seasare increasingly turning to charters.

According to "The State of Wealth, Luxury and Yachting"report released this week by researcher Wealth-X and yachtmanagement and sales firm Camper & Nicholsons,ultra-high-net-worth individuals, defined as those with a minimumnet worth of $30 million, took 21% more charters in 2015 than inthe year prior.

"Sales vs. charters is always a big discussion withclients," said Barbara Dawson, a senior charter broker withCamper & Nicholsons. “I think for some, the fact of being ableto walk on and experience what that yacht has to offer for one weekand go away, leave all the troubles behind, it’s a big plus. Theydon’t have to worry about the chef needing a month off, the captainneeding to go into the yard, the engine has blown. They don’t wantto have to manage.”

A week on a superyacht can cost $115,500 to $190,000, onaverage, the report found, while the average purchase price is abit more than $10 million — 268 superyachts sold in 2015,compared with 271 in 2014 and 242 in 2013. The average charter feewent up slightly, 1.3%, from 2014 to 2015.

Ultra-high-net-worth individuals who do opt for purchases end upchartering their yachts out to others to offset the steepmaintenance fees, but these vessels are more money sucks than cashcows. For the $10 million superyacht, the annual maintenance comesin around $1 million, meaning the boat will have to spend betweensix and nine weeks being chartered to reach a break-even point,depending on what it can fetch on the rental market.

[Related: Read "In the boat and yacht market, there's smoothsailing ahead."]

“You will help offset maintenance, but that’s barring nomechanical breakdowns of major consequence, and it also depends onlocation and your crew,” Dawson said.

If a superyacht is kept in the Caribbean, Dawson estimatedit will be chartered only three to five weeks a year.Superyachts in the Mediterranean end up rented eight to 12weeks a year, she said. With agent fees and value-added taxescutting into the profit, there’s no guarantee that putting asuperyacht up for charter will recoup the owner’s maintenancecosts, despite the growing popularity of chartering.

There are also some ultra-high-net-worth individuals charteringyachts to determine if they’re interested in making a purchase, andothers who charter to travel to more adventurous destinations. Anew wave of superyacht enthusiasts prefers traveling to remotelocations. “It’s more convenient, in the sense that they cancharter where they want to and not have to worry about moving theyacht,” Ben Kinnard, a research analyst with Wealth-X, said. “We’veseen a trend [to] trying out new destinations. If you want totry out Asia one month and Antarctica the next, there’s a lot ofhassle if you own the yacht.”

[Related: Read "Managing the risks of high-net-worthclients' global travels."]

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