DATUM
Expeditions measured from sea level Plan an expedition
Two climbers standing on a ridge crest, silhouetted against a pale morning sky.

Everything you know is at sea level.

DATUM plans guided expeditions by elevation, not by itinerary. This page begins 5,364 metres above the datum and ends 30 metres beneath it.

Khumbu · Nepal

28°00′N 86°51′E

Everest Base Camp · 5,364 m

A datum is the surface everything else is measured from.

Mean sea level. Zero.

The line every altitude on earth is quoted against.

Most travel is sold sideways. One city, then another city.

We sell it vertically.

Five places on this page. Each one sits at its true published elevation, and you can only go down.

The instrument on the right is reading your position. It is the only navigation here.

A lone acacia on the plain at dawn with volcanic highlands behind it.
Rim, first light
Acacia trees in silhouette under a heavy storm sky.
Weather coming off the highlands
A single flat-topped acacia in pale gold haze.
The floor, mid morning
Acacia and open grassland with distant hills at sunset.
Climbing back out before dark

2,340 mNgorongoro · Tanzania

Cold nights on the rim of a volcano.

The crater rim is high enough that you want a fleece at dawn, and most people are surprised by that. Six hundred metres below it the floor keeps its own weather, its own herds and a soda lake that goes pink when the light drops.

You descend into it after breakfast. You climb back out before dark, because the road up is not a road anyone should meet at night.

Guanacos on grassland below the snow-covered Cuernos del Paine.
The granite towers of Torres del Paine under a streaked sky.
Low sun on the golden granite faces of the Cuernos del Paine.

1,180 mPaso John Gardner · Chile

The pass gives you the ice field all at once.

You climb through beech forest for three hours with no view at all. Then the trees stop, the wind arrives from the west, and the Southern Patagonian Ice Field opens across the entire horizon. Most people sit down.

Route
O Circuit
Highest point
1,180 m
Season
Nov to Mar

Method

A route is a set of decisions made months early.

Weather windows, permits, acclimatisation nights, and the way down you hope not to use. The itinerary is the last thing we write, not the first.

A climbing rope and carabiner resting on a folded topographic map.

01

Ground truth

We walk it ourselves, in the season we sell it, or we do not sell it.

A compass resting on a topographic map.

02

The window

Departures are set against decades of local records, not a brochure season.

A person sitting outside a tent reading a paper map.

03

Height per night

Metres gained per sleeping night is a planned number. It decides who arrives.

Expedition equipment laid out in a grid: boots, pack, camera, map.

04

Permits

Some of these take a year. We start them before anyone has paid us.

A coiled climbing rope with carabiners in low light.

05

The way down

Every day carries an exit that does not depend on a helicopter arriving.

A camp table with a map and an enamel mug.

06

Your guides

[ Guide roster, certifications and years in region to be supplied by the client. No figures are invented here. ]

A lenticular cloud burning orange above the Paine massif at sunset.

07

What we will not do

We will not run a departure we would not put our own people on.

180 mDanum Valley · Borneo

No horizon anywhere.

A hundred and eighty metres above the datum, and you cannot see forty of them in any direction. The canopy closes over the top of everything.

Distance stops being something you look at. It becomes something you listen to.

A dark coastline at dusk with surf running onto the sand.
A split level photograph: an island above the waterline, a reef and a swimmer below it.

Zero.

Sea level is not a place. It is the agreement that lets every other height on earth mean something. You are about to go through it.

A reef wall dropping away into open blue water with a diver in the distance.

−30 mRaja Ampat · Indonesia

Thirty metres under the agreement.

Below the datum the numbers keep going and nothing else does. Weight leaves first, then direction stops mattering. People surface saying it was the quietest they have ever been.

  • −5 mRed has already gone out of the world.
  • −18 mOrange and yellow follow it down.
  • −30 mBlue, and no weight at all.

Choose your elevation.

5,364 mKhumbu Traverse NepalEnquire 2,340 mNgorongoro and the Crater Floor TanzaniaEnquire 1,180 mPaso John Gardner, O Circuit ChileEnquire 180 mDanum Valley Primary Forest BorneoEnquire −30 mRaja Ampat, Four Kings IndonesiaEnquire

Tell us the height you want to wake up at.

Plan an expedition

Enquiry

Start with the elevation. We will work out the rest.

A real person reads every one of these. Expect a reply within two working days, with questions before an itinerary.