I stare abstractedly at the bubbles streaming in our wake, marking momentarily our passage before disappearing. For a while longer a path of smoother water remains, before merging once again with the rest. Like our own existence, in a way. I think of the thousands of other seafarers that have travelled the same way before us. How many Stone Age people thought the same as they paddled these routes in their hollowed-out tree-trunks, how many Vikings in their long-ships, how many medieval traders in their skutes, how many modern day sailors like ourselves? Each must have left similar trails, each has now gone.

The mists of time swirl. My mind takes me back to when the Baltic Sea is starting to form. A large depression in the rock of the ancient continent of Baltica starts to fill with sediment from erosion of the surrounding land. Much later, a river, the Eridanos, flows through the basin, deepening it and carrying much of the sediment out to the North Sea. Millions of years later, the ancient continent of Laurentia collides with Baltica and compresses the Baltic Sea into the elongated shape it is today. In the last two million years or so, glaciers cover the depression, leaving behind a vast freshwater lake called Ancylus when they eventually begin to melt. Eventually the North Sea breaks through the shallow Danish Straits where we are now and the Baltic Sea becomes the brackish water body that it is today. The islands of the Danish archipelago and the surrounding shallow straits are all that remains now of the barrier that once separated the lake from the sea.

“You look as if you are daydreaming again”, says the First Mate. “Look, why don’t you go and make us a cup of tea? That’ll wake you up.”

We are on our way from Bogense to Middlefart. The wind is gusting from the north-west, and we are sailing close-hauled. The First Mate is helming to get some practice handling sudden gusts. I dutifully do as I am told, and bring out two steaming mugs.

“You know”, she says. “I could get used to this.”

“Used to what?”, I ask. “Helming, or me doing as I am told?”

She doesn’t hear me.

We are approaching Middelfart. In the distance, we see the New Lillebælt Bridge spanning the narrow Snævringen channel between Jutland and Fyn. From this distance, the cars and trucks crossing it look like tiny Matchbox toys. We need to go underneath it.

“I have been thinking”, says the First Mate. “You can’t write Middelfart in the blog. It’s too rude. The automated censors will pick it up and delete it. Can’t you think of some other name?”

“Yes, you are quite right”, I say. “I think I will call it Bottomfart. That sounds much better.”

“Well, at least the blog will have something for everyone”, says the First Mate. “Even six-year-olds. Look there’s a navy ship following us. They’ll keep you in line.”

Sure enough, there is a patrol vessel not far behind us. The AIS shows that it is doing eight knots, so it will soon catch us.

“They probably think we are smugglers”, I say to the First Mate. “I hope you hid those bottles of whisky.”

“They are more likely to think you are an illegal immigrant from the UK now that it’s a third country”, says the First Mate.

“Whatever”, I say. “Let’s see if we can outrun them.”

I push the throttle forward. Our speed increases from 6 knots to 6.2 knots.

“Well, that didn’t make a lot of difference”, says the First Mate. “We’d better hope they run out of fuel or something.”

The patrol vessel continues to gain on us. As we pass under the New Lillebælt Bridge, it slows and loops around and heads back in the direction it came from. Either they have decided that we are not carrying anything worth making a fuss about, or we weren’t the target in the first place. Probably both.

We follow the Snævringen channel around to the right and then to the left. Two porpoises surface close by, as though to welcome us. In the distance we spy the forest of masts of Middelfart Marina and head for there. Before long, we are tied up on the end of one of the finger pontoons.

“Let’s get the bikes off and go for a ride into town”, says the First Mate. ”I read that it is about a kilometre or so. We can have a look around and then have a coffee.”

Apparently the name of Middelfart derives from the Old Danish for ‘Middle Way’. It was originally used for the Snævringen channel between Jutland and Fyn that we had just come through, but later was applied to the town that grew up around it. In the Middle Ages, the town had specialised in catching harbour porpoises.

“The guidebook says that only selected families were allowed to hunt the porpoises, a privilege given to them by the king”, says the First Mate. “They used to line their boats up across the narrowest part of the channel and beat the water with their oars to frighten the poor things into the shallow areas where they were killed. Their blubber was used to extract oil for lamps. When electricity came along, there was no need for much oil any more, and hunting for porpoises stopped. Now it is illegal.”

“Perhaps that was what the patrol vessel was doing”, I say. “Making sure that foreign boats don’t do anything to the porpoises. As if we would.”

We sit and have an ice cream opposite the church.

“The Danish certainly have managed to preserve a lot of their medieval buildings”, says the First Mate. “Look, there’s one over there that was built in 1584. I might have a look around for some more interesting doors.”

We end up at the small harbour on the north side of the town. Several traditional boats are tied up there.

The next day it is bright and sunny.

“I take your point about our tyre marks from Kolby Kås”, I say at breakfast. “They just don’t seem have started a trend. I think I am going to clean them off this morning.”

I fetch the hose from the pontoon and start scrubbing. It’s tough work but eventually the black marks are gone.

“Here, let me get a photo of you”, says the First Mate. “It’s not often I see you working so hard. I need a record for posterity.”

The shutter clicks.

“Oh no”, she says, looking at the small screen. “It’s made you look like the Mannikin Pis statue we saw in Bogense. We can’t put that in the blog.”

“Well, at least the six-year-olds will find it funny”, I say.

We decide to have lunch at the small restaurant near the marina office.

“I was talking to one of the people along the pontoon this morning”, says the First Mate. “Apparently there is a very nice path from here out around the promontory and back into Middelfart. Why don’t we go for a cycle along it after lunch? I have a map, so we won’t get lost.”

“That sounds like a good idea”, I say. “It’s a nice sunny day for it.”

After lunch, we set off. The path leads along the shoreline, past a small yacht harbour, then into some woodland. There are beautiful views out over Fænø Sund towards Lænkevig, and we sit for a short time on a bench taking it in.

“That looks like a nice place over on the other side”, I say. Perhaps we can anchor over there tonight. It’ll be nice and peaceful and we will also save on marina fees.”

“That’s a good idea”, says the First Mate. “Let’s do that.”

We push on. The track becomes narrower and rougher.

“Are you sure this is a cycleway?”, I ask.

“I am sure it will get better just up around this corner”, says the First Mate.

We reach the corner. The track gives way to a small sandy beach. Two woman are there, enjoying the sun. They look surprised to see bikes on the beach. I smile at them, pretending that we are beach inspectors come to check the quality of the sand. I scuff the sand with my foot. They don’t look convinced.

“Over there”, says the First Mate, pointing. “I can see the track leading up the hill at the other end.”

It does. But it isn’t a cycle track any more. Even calling it a walking track is being generous. We lug the bikes to the top of the bluff overlooking the beach. Another path leads in the general direction we want to go. The gnarled tree roots criss-crossing it make it unrideable, on our small bikes at least.

After ten minutes, we reach a huge gully blocking the way. The path leads down then up again on the other side.

“Let’s have a look at that map”, I say.

We are on a brown line snaking its way around the promontory. The key says that it is a walking track with a classification of three ‘boots’. Another key explains that three ‘boots’ mean that it is a strenuous hiking route and strong footwear is advised.

“I don’t think that this is a cycle route”, I say. “Did the chap you talked to really say it was? He must be into mountain biking.”

“No, he just said it was a nice route”, says the First Mate. “I just assumed that we could cycle along it.”

I stop myself from gnashing my teeth. I am not sure if our travel insurance covers self-inflicted dental damage, especially in Denmark.

We backtrack along the bluff and come across a camping site. At least there is a road leading out of it. We follow that and come to a small café.

“Let’s stop here and have something to drink”, says the First Mate. “I am getting tired and thirsty.”

Just as we are locking our bikes, the local Hell’s Angels chapter arrives.

“I’ll find us a table outside”, I say, remembering my encounter with Nebraska Man in the laundry on Terschelling. “You go and order. I’ll have a cup of tea. Earl Grey, please.”

“How did you get on with the bikers?”, I ask the First Mate when she returns. “Did they push in in front of you or beat anyone up?”

“Not at all”, she says. “They were very courteous. One even picked up my money for me when I dropped it.”

In the evening, we sail across to the other side of Fænø Sund to Lænkevig and drop anchor. A few other boats are already there, but there’s enough space. We sit in the cockpit drinking wine and watching the sun go down behind the trees. There is an ethereal quality to the light.

I pick up the book I am reading at the moment, Life after Growth, by Tim Morgan. In it, he talks about the era of growth that we have become accustomed to being over. It’s all due to the availability of energy – there is no shortage of energy as such, but what is important is the amount of energy that is extracted per unit of energy expended, or Energy Return on Energy Input, EROEI for short. At the beginning of the Age of Oil, the average EROEI was around 100:1, meaning that each unit of energy input would yield 100 units of energy output, so that there were 99 units of net energy available. Since then the EROEI has declined drastically, so that now the global average value is around 15:1. North Sea oil is even as low as 5:1. Obviously, when the EROEI gets to 1:1 the energy extracted is the same as the energy input, so there is no net gain. Apparently when the average EROEI gets to between 8:1 and 4:1, economies cease to be viable, as so much energy needs to be expended obtaining energy that there is not enough surplus energy for all the other things in the economy. Agriculture, for example, needs a lot of energy and natural gas to produce fertilisers and pesticides. Without those, we can’t grow crops, and won’t be able to feed the global population.

What to do? Renewable sources of energy will help but may not be enough. Wind-farms have EROEIs around 17:1 and solar panels between 7:1 and 9:1. Biofuels are around 2:1, and also need more land than world’s current cropland. Nuclear power may be an option, but the problems are public opposition and scaling up – 15 times the current number of stations would be needed. In the short term, we need to become much less wasteful of energy – more use of public transport, living closer together to improve energy efficiency, less consumption. But in the long run, we will need to develop a new economic model not based on growth. It will be a profoundly different era to what we are used to.

“What’s the book about?”, asks the First Mate, topping up the wine glasses.

I tell her.

“Can’t you find something more cheerful to read?”, she says. “Especially in such a beautiful place as this?”

“It is what it is”, I say. “Maybe we should just stay on the boat and live the simple life.”