Exciting working day: This is what a petrol station attendant experiences at the Strande yacht filling station

Monday morning, nine o'clock. Grey clouds hang low over the Kiel Fjord. You would think that there is not much going on in Strande's municipal harbour at this time of day. But far from it. At the far end of jetty 6, Thomas Langer has already been whirling for two hours. Langer is the petrol attendant at the yacht filling station and something unusual happened the day before - he ran out of fuel. The explanation is quickly found: It's Kiel Week and for Thomas Langer that simply means: a state of emergency.

"What was going on yesterday?" asks a friend who is inserting the petrol nozzle into the filler neck of his inflatable boat. Apparently the news has travelled fast. "Why?" asks Langer dryly, adding: "With the rush, after a weekend like this: It can happen."

It was the first hot summer weekend of the year. Everything that could swim was on the water. The regular sports boats were joined by numerous coach, support, jury and buoy laying boats, which supported the sailors on the regatta courses.

The customers of the Strande yacht petrol station

During Kieler Woche, the inflatable boats with their large outboards make up the majority of Langer's clientele. And they all come at the same time - either in the morning before or in the evening after the races. However, the reserves at Langer's petrol station are limited. Supplies are only available on weekdays. If larger boats with bunker capacities of over 500 litres are added to the mix, things can get tight. "I try to avoid that, but sometimes there's no other way," says Langer. And so it was over by the afternoon. He had to put off those who came away empty-handed until the next morning.

At 7 a.m., the long-awaited supplies finally arrive and the tanker lorry is ready. It comes three times during Kiel Week. Normally it is less frequent. It has loaded a full 11,000 litres of super petrol, which now flows through pipes from land to the yacht filling station. Hoses with the diameter of street lamps are laid under the planks of the jetty for this purpose.

Thomas Langer can store a total of 23,000 litres - 11,000 litres of premium petrol and 12,000 litres of diesel - in his tanks. They are located directly under the steel pontoon, which is securely fastened to two large piles against changing water levels. In addition to fuel, he sells everything you need on board - from engine oil and chocolate bars to bottles of rum.

It takes two to three hours for the petrol to change tanks. At a road petrol station, it takes five times as long. But the pipes are too narrow and the pressure at which the super flows through the pipes is too low, says the lorry driver. It's quicker with diesel.

How Thomas Langer keeps an overview

While the desired fuel is delivered from shore, it is immediately withdrawn on the other side of the petrol pump. The petrol nozzle is passed between the inflatable boats without interruption. As soon as one boat leaves the jetty, another follows. This goes on all morning. Meanwhile, Thomas Langer rushes all over the pontoon. "What about you?" he asks the three-man crew of a coach boat. They have found a free space, are waiting and chatting, although the next petrol pump is already free. "Here," says Langer and presses one into their hands. "Go on!" And then he's gone again, because someone in the ticket office wants to pay their bill.

Read more from this series:

• Harbour master up close during Kiel Week
• Non-stop work as a boatswain on a museum ship
• Why a retired captain works as a lock keeper
• Dreams come true at the Sirius shipyard
• Students at the sailing boarding school give their all for the dream of the Olympics
• From the roll of cloth to the finished sail at the sailmaker's
• How a captain of the road transports yachts
• Attention, control! On the road with the water police

If you watch Thomas Langer at work, it quickly becomes clear that these eleven by four metres are his territory. Like a conductor coordinating his orchestra, he leads the pleasure craft drivers at his petrol station. His instructions are clear, his commands precise. And they have to be, so that the hustle and bustle is organised.

The way to the petrol station attendant

He himself remains the calm personified. Thomas Langer belongs to the Strande yacht petrol station like the Friedrichsort lighthouse belongs to Kiel. He has been keeping the shop running for 18 years. Several newspapers have already reported on him. People know him and he knows people. The now 70-year-old ended up working as a petrol station attendant by chance.

Born in North Rhine-Westphalia, he came to the north when he was ten. After school, he learnt the trade of radio operator and worked for the navy in Eckernförde and Flensburg. But at some point, radio operators were no longer needed. And despite retraining for merchant shipping, he had to find a new job. What followed was an episode of odd jobs: at times he drove a taxi, worked as a diving instructor in the Red Sea, looked after difficult boys in the Canary Islands, crossed the Atlantic and lived on a kibbutz in Israel.

In 1994, at the age of almost 40, he changed tack again and trained as a shipbroker. But after he graduated, there was little demand in the Kiel area: ferry traffic, as it exists in Kiel today, was not yet a thing and the low price of diesel meant that freighters avoided the Kiel Canal.

So the jack-of-all-trades changed direction again and eventually found his way to Strande. Initially, Langer took on the role of harbour master as a deputy in 2006, until another opportunity arose shortly afterwards. The yacht petrol station in the harbour was looking for a new petrol station attendant. This suited the passionate sailor and sports boater.

What does he particularly like about the work? "Nobody is looking over my shoulder. I'm my own boss," he says. Langer does everything himself, from ordering fuel to purchasing the shop's range: "It's simply a nice place to work with a really pleasant audience. I also have a great view.

This is regularly enriched by extraordinary boats. The largest vessel Langer has seen here was a 100-foot yacht a few years ago. But navy boats, motor yachts with up to 6,000-litre tanks, supply catamarans for wind turbines and yachts with helicopters on deck have also moored here. Langer collects the photos on his mobile phone. In some pictures, the petrol station is barely recognisable because of all the boats. "Sometimes there are some crazy boats in there."

Fill up reserves for the yacht refuelling station

It is now midday in Strande harbour and the petrol station is gradually becoming quieter. Hundreds of litres of petrol have been sold this morning, while the diesel pump has so far remained unused. That's no wonder during Kiel Week, says Langer. What's more, the weather is not particularly inviting: it keeps raining and a strong westerly wind is blowing across the fjord.

"What's more, a surprising number of people bunker their boats with canisters," he says. However, this only works until they have the diesel pest in their tanks. The slimy residues that clog filters and damage engines are caused by microbes. These thrive when water collects in the tank, for example through condensation. The bio-components in diesel, which have had to be added to road petrol stations since 2008, further exacerbate this problem.

At the yacht petrol station in Strande, diesel is sold without the bio additive. This makes the marine fuel slightly more expensive, but also less susceptible to diesel pest. On this day, a litre of diesel costs 1.96 euros. Super petrol is 2.08 euros. One litre of a diesel additive, which is also available from Langer, and pleasure boaters are on the safe side.

Just like Anni and Rainer Decker. They also want to be prepared - but for their holiday. Their holiday is fast approaching and their diesel reserves need to be topped up. They moor alongside their sailing yacht, a Hallberg Rassy 312. "You often don't have much choice on the way," says Anni Decker. "You have to think carefully about where to get which fuel."

A service that people appreciate

Langer supports the two of them during the mooring manoeuvre. The wind is unfavourable, directly onto the tank pontoon. When the two are moored, Langer immediately starts looking for the fuelling nozzle. In contrast to smaller motorboats, Langer refuels larger yachts himself. The risk of a mess is simply too great, he says. Like with a car - stick a gun in and wait for it to click - it often doesn't work. This is because on many boats, the vent is positioned too low, so that the automatic stop function of the fuelling nozzle only triggers when the tank is already overflowing.

To prevent this, he places one ear directly on the filler neck of the boat while refuelling and listens to the sound of the diesel. A local newspaper has already dubbed him the "petrol whisperer". As soon as the tank is full and the diesel rises up the pipe, the noise changes. This is the signal for him to stop refuelling.

A service that people appreciate: "It means the harbour is always clean; no messes happen. In addition, I also have the best rum selection east of Trinidad here!" To get his service, pleasure craft have to moor in such a way that Langer can reach the filler neck from the pontoon: "I don't crawl over boats on all fours to get to the filler neck on the other side. I don't do that." But mooring correctly is enough of a hurdle for some skippers, as it turns out a little later.

Challenges on the pontoon

A Bavaria is travelling far too fast, pushed by gusts from astern, towards the long side of the pontoon. "That's too fast and your fenders are hanging way too high," Langer shouts to the skipper as the hull rumbles against the jetty - and the yacht comes to a halt. It remains a minor shock, but Langer knows that it won't be the last time. Thomas Langer explains that charter skippers in particular have problems with the mooring manoeuvre time and again. Many are not yet familiar with the hired boats and have little experience anyway. Lines are then thrown into the water and fenders are attached incorrectly or not at all. "In onshore winds, they often bang into the corner," says Langer, pointing to a well-padded edge at the edge of the pontoon.

But even long-standing owners have their difficulties: At his old ticket office, which was replaced three years ago, an elderly skipper once drove the bowsprit of her motorsailer into the window.

Six months later, her son caused a stir with a similar manoeuvre. "The bowsprit was too long then too, and the petrol pump was askew." People simply don't sail enough, says Langer. Many boats spend most of their lives in the harbour.

Recurring hustle and bustle at the Strande yacht petrol station

In the afternoon, the yacht refuelling station becomes fuller again. The races have been cancelled due to the wind, and the sailors and dinghies return to the harbours like bats to their caves. Many now want to refuel - and for Thomas Langer, the hustle and bustle starts all over again.

This will continue for the rest of the week and the petrol pump will be besieged with premium petrol in the mornings and afternoons. After that, more diesel will flow through the pipes again. This is when the holiday season begins in northern Germany and many pleasure craft will be out on the North Sea and Baltic Sea with their engines running.

The Strande yacht petrol station is still open every day until October. Then it's over - for Thomas Langer too, as he wants to give up his full-time job next year. He then has other projects lined up that he wants to devote himself to as a retiree.

Refuelling safely and efficiently: what to look out for

• Safety equipment: Fire extinguisher and fire blanket within reach
• Switch off the engine and switch off all electrical devices
• Check fuel filter regularly and replace if necessary
• Avoid overfilling, request help if necessary
• Wipe up spilt fuel immediately and dispose of it properly
• Document refuelling process with quantity and date