After all the fuss over his suggestively shaped space rocket, it seems Jeff Bezos is still obsessed with the idea that size really matters.

The world’s third-richest man (behind Elon Musk and LVMH CEO Bernard Arnault) is building a megayacht in Holland on a scale so excessive that it looks like the boat from “Gulliver’s Travels” washing up on the island of Liliput.

To get out of the Rotterdam harbor where it is being built, a bridge will have to be dismantled.

The $500 million Y721 will be, at 417 feet long, the biggest sailing yacht in the world when it launches this summer. In a pissing match with other tech billionaires — Google co-founder Sergey Brin, Oracle co-founder Larry Ellison and media mogul and new People magazine owner Barry Diller — Bezos, 58, wins.

In fact, even his yacht’s secondary support boat is bigger than Brin’s elegantly futuristic $80 million yacht, the Dragonfly.

The Y721’s main vessel boasts three decks — one with a swimming pool — and, with three gigantic masts, it can claim eco-credentials by being powered largely via a cutting-edge propulsion system that harnesses kinetic energy under sail.

Still, the Y721 will cost around $25 million a year to run. There is space for 18 guests on board, and it will require a crew of 40. Inside, it is said to be modeled on Diller’s yacht, Eos (a favorite of celebrity friends including Kate Perry, Prince Harry and Bradley Cooper) — although Eos stretches out a mere 305 feet. (When Diller bought it, the boat was the largest private sailing yacht in the world.) Ellison’s Musashi, meanwhile, comes in at 288 feet, while Brin’s Dragonfly is just 240 feet.

Its tender will carry toys such as jet skis and smaller boats and also provide a helicopter landing pad — vital as Bezos’ high-flying girlfriend Lauren Sanchez, 52, likes to fly her beau on dates

The half-billion price tag is a relative drop in the ocean for the Amazon founder, whose net worth was valued at $181 billion by Forbes this week.

And yet, not everyone is impressed.

“If I was Jeff Bezos I would have gone for something a bit more radical, but it is a big yacht, which I guess is the point,” said Russell Crump, an independent broker of bespoke yachts. “It will be beautiful . . . Oceanco are the biggest and the best builders in Holland.”

The key word there is “biggest”: Even without the masts, Bezos’ yacht reportedly stands at over 131 feet tall, meaning Oceanco will have to temporarily dismantle the Konigshaven Bridge, known as De Hef, to allow the boat to pass.

Local authorities are expected to debate the request later this month, while a petition against it has been launched by local opponents (who have threatned to pelt the boat with rotten eggs) and collected more than 58,000 signatures.

“This man has earned his money by structurally cutting staff, evading taxes, avoiding regulations and now we have to tear down our beautiful national monument?” Rotterdam politician Stephan Leewis tweeted of Bezos. “That is really going a bridge too far.”

Oceanco declined to confirm that Bezos had commissioned the new boat.

But will Bezos be able to top the others in the name department? One suggestion: The Compensator.

Here are the tech titans’ boats by the numbers:

Y721

Owner: Amazon founder Jeff Bezos
Cost: $500 million
Features: Three deck levels, a swimming pool, a helicopter landing pad on the tender and a kinetic-propulsion system.
Length: 417 feet
Speed: 20 knots
Passengers: 40 crew, 18 guests
Running costs: $25 million a year

Eos

Owner: IAC chairman Barry Diller
Cost: $200 million
Features: Interiors designed by the late François Catroux, known for his “grand coziness.” Pool on top deck. Figurehead of Diller’s wife, fashion designer Diane von Fürstenberg, created by sculptor Anh Duong.
Length: 305 feet
Speed: 16 knots
Passengers: 21 crew, 16 guests
Running costs: $7 million a year

Musashi

Owner: Oracle co-founder Larry Ellison
Cost: $160 million
Features: Spa, swimming pool, outdoor gym and movie theater
Length: 288 feet
Speed: 12 knots
Passengers: 23 crew, 18 guests
Running costs: At least $10 million a year

Dragonfly

Owner: Google co-founder Sergey Brin
Cost: $81 million
Features: Open-air cinema, Jacuzzi and sundeck that converts to a dance floor
Length: 240 feet
Speed: 25 knots
Passengers: 16 crew, 14 guests
Running costs: $7 million a year