Billed as the ‘busiest shipping lane in the world’ (although those of us who have sailed across the English Channel might disagree) we weren’t looking forward to dodging between the behemoths in this narrow channel.

Those bulk carriers, containers, tankers and passenger ships push through in fast and relentless caravans from east to west and west to east. We were heading south to north.

In addition to the motorway traffic, tugs and barges slowly skirt the edges of the lanes at their own angle, while ferries cross-cross the waters between Sumatra, Singapore and the Malaysian peninsular.

And then there are the tiny Indonesian fishing skiffs which sit in the slim buffer zone between channels. To make this a smooth operation, you need to use every navigation system at your disposal.

We rely on AIS, radar, Navionics, binoculars and the most important resource of all: Mark One Eyeball.