It’s the only time you’ll want to put your Aston Martin under water.

The British automaker unveiled its first submersible design Thursday at the Monaco Yacht Show. Dubbed Project Neptune, it’s a three-person vehicle with silver, blade-like pontoons and an acrylic bubble of a cabin for maximizing underwater views.

Aston Martin expects the sub will be available in about a year and will be priced around $4 million, the company’s chief creative officer Marek Reichman told Bloomberg. For comparison, a V8-powered DB11 will run you nearly $200,000.

Reichman said the company plans to build no more than a dozen of the submersibles per year. “If you think about Aston Martin, we are a very exclusive brand,” he said. “In 100 years, we’ve only made 80,000 cars.”

Neptune is a collaboration between Aston Martin Consulting, the company’s design consulting arm, and Florida-based Triton Submarines, which has been making luxury submersibles for a little more than a decade.

The model is based on Triton’s Low Profile (LP) platform, specifically designed for superyachts. At just 5.9 feet tall and 8,800 pounds, it’s the lightest and smallest three-person sub in production in the world, according to the company. It’s capable of diving to 1,650 feet, has a speed of 3 knots, or 3.5 miles per hour. It is also air-conditioned.

Aston Martin has gradually been expanding into other luxury areas. Last year it unveiled the AM37, a 1,000 brake horsepower motorboat created with Quintessence Yachts and Mulder Design naval architects. It has also partnered with Miami-based G&G Business Developments on Aston Martin Residences, a 400-unit waterfront condo project in downtown Miami.

Reichman said the company had done extensive research into what high-net-worth individuals were interested in purchasing other than cars. Unsurprisingly, many are into boating.

“Those superyacht people, what they want to experience is changing,” he said. “It’s no longer about just having a launch or having your tender. It’s about having some other way of entertaining your guests.”

This article was provided by Bloomberg News.