‘I took a call from Emerens Ericsson early this morning,’ Bram went on. ‘He’s the head diver in charge of the Defence Diving Group, based in Den Helder. Rob gave him my number. He wanted to know exactly who was there when we found the artefacts and where we all were, what positions, when the items were recovered. The boat’s prepped and I refilled everyone’s air tanks this morning. Conditions look good. We’re looking at a slack tide with minimal surge. It’s supposed to rain later, but we should be well and truly home by then.’

Nico caught my eye. ‘What about Jo?’

Bram turned his assessing gaze on me. ‘How about it, Jo?’

I was already shaking my head. ‘I can’t.’

‘Why not? Your certification’s current,’ Nico said. ‘Only yesterday, you were telling me how much you wished you could go down and take a look at the wreck yourself.’

‘My skills are a bit rusty,’ I said. ‘And I wasn’t on the original dive. I’d only get in the way.’

‘Nonsense,’ said Nico. ‘I’ll look after you. We all will.’

‘The most important thing to remember is that we need to demonstrate our professionalism. We want the Defence divers to understand we’re into preserving Dutch history and just as committed to the cause as they are.’ A hint of a smile teased the corner of his mouth. ‘We just have more fun doing it.’

‘I’ll stay on the boat,’ I said. ‘I’d like to take some notes about the location.’

Bram shrugged. ‘Suit yourself. The offer’s there, if you change your mind. There’s an extra suit and tank.’

A sudden noise came from the water and we turned towards the marina. Through the window we saw a sleek yacht rounding the headland and speeding towards us, lights flashing. Bram led us outside for a closer look.

From my diving experience, I knew enough about boats to recognise that the vessel, a Dutch Craft 56 with twin engines, could easily accommodate the six crew members ranged along its oversized aft deck. It was a top of the line performance yacht, powerful enough to handle both rough seas and deceptive trenches of shallow water concealing dangerous coral reefs. Bram’s boat, Proteus, was, by contrast, an older-style sports boat. In a voice tinged with pride, he’d described the worn wraparound lounges he’d removed to create more deck space between the transoms fixed across the sternpost and the large fibreglass tank racks he’d installed behind the pilot house so the divers could quickly access their gear. Despite these modifications, there was no comparison between the two vessels. When the Navy boat pulled in beside it, there was no disguising the Proteus’ age nor the battered hull which gave it the appearance of a used fridge nearing the end of its life.