‘Don’t touch!’ – an expedition cruise ship with two submarines docks in Dublin Port

Consider the subs “the ultimate luxury perk on the ultimate luxury expedition ships”, the line says.

And whatever about the fancy suites, spa and restaurants on board, by the time my tour group hit the submarine bay, I felt like I was 12 again.

“Don’t touch!” the pilot joked as I peered into its bubble domes. “That glass is $500,000!”

Cruising brings to mind floating resorts with bottomless buffets, waterslides and Broadway-style shows, but there’s a lot more variety to it than that.

“There’s been an explosion in expedition tonnage,” says travel agent John Galligan, whom I met on board.

As well as a lecture theatre, library, photo studio and ‘mudroom’, where guests get suited and booted for adventures, Venture’s kit includes 24 pitch-black Zodiacs that nip in and out of off-grid spaces — from Greenland’s glaciers to Antarctic beaches popping with penguins.

The ribs are the ship’s “workhorses”, Jen Martin of Seabourn Expeditions explains. “We don’t need a dock.”

Expedition cruises range from basic ships with few frills (eg Hurtigruten) to intrepid itineraries for fit, casual travellers (eg National Geographic Expeditions) or luxe ships from the likes of Silverseas, Viking or Seabourn. Carrying 264 guests and built at a cost of $225m/€208m, Venture is the line’s first purpose-built expedition vessel (Seabourn Pursuit follows later this year).

I’d describe its level of luxury as very comfortable rather than mind-blowing. All suites have ocean views and are decently sized (cruise staterooms are usually smaller than hotel rooms), with underfloor heating, walk-in wardrobes, gear-drying cupboards and Swarovski Optik binoculars. As well as a small pool with hot tubs, there are two restaurants, fne wines and lounges that mix boutique hotel and ski lodge vibes... complete with furs and faux fires.

Standing on its bowsprit, I imagined watching the strengthened hull negotiate ice below, and chatted with one of the 24 expedition leaders on board. These range from botanists to geologists and ornithologists, and they’re very accessible between talks and trips — Seabourn says its sailings are not about box-ticking, but enrichment.

“We want to connect people to a place,” says Martin.

Sailings are all-inclusive, meaning meals, drinks and Zodiac trips are included — though top-end stuff like Scuba dives, kayaking or submarine adventures are extra. You can budget up to $999 for a spin in the subs, which can go to 300m deep and even explore shipwrecks.

And the prices?

A 15-day Iceland and Greenland itinerary costs from €6,301pp this summer; 36 days including the Northwest Passage is five times that (seabourn.com).

Yet Galligan says a small but growing number of Irish guests are stepping on board — be they wealthy travellers or retiree bucket-list trips funded by pension lump sums.

"We see growth potential within the Irish market for ultra-luxury and expedition voyages and will be working with key agent partners," a spokesperson for Seabourn says.

"We carry guests of all ages with most abilities,” they say – so you don’t need to be Ernest Shackleton. Activities can be tailored to individuals’ fitness and ability levels, submarine pilot Isaac Yebra tells me.

“Think expeditions with champagne,” he says.