Boating in summer10 tips to beat the heat

Michael Rinck

 · 14.08.2025

When it's hot, the only thing that helps is cooling off in the sea. Don't forget: Reapply sun cream after swimming
Photo: Martin Morell
The heat of the last few days is almost unbearable, even at sea. To make sure it's still a great trip, tried and tested countermeasures and some accessories can help

Cooling by bathing

Engine off and into the water - still the best way to cool off at sea. A fender on a floating line is just as much a part of the bathing routine as unfolding the bathing ladder in good time. And don't forget to reapply sun cream after swimming!

Utilising evaporative cooling

According to the laws of physics, evaporation creates cold. This can be utilised in somewhat inelegant ways, for example by hanging damp cloths in hatches and companionways to protect yourself from the summer heat. The smart solution: wet your cap and T-shirt regularly - the effect is naturally greatest directly on the skin. Incidentally, bottles also cool down when a wet sock is put on them.

Protect food

  • On-board refrigerator: The appliance is suboptimal in two respects - it consumes electricity and it offers little space. This makes it all the more important to utilise it optimally. The on-board cooler works best when it is well filled - then little cold air can escape in exchange for warm air when it is opened. The cooling capacity can be increased with a trick: You can add frozen cooling elements (better rectangular solid ones than cooling bags) if there is still space, or deep-freeze juice cartons and use them as replacement cooling elements, so to speak.
  • Alternatives: For fruit, butter and jam, overnight refrigeration is often enough to keep them edible for a long time. If there is no room in the fridge, they can be wrapped in a box in a high-quality sleeping bag during the day and are only a few degrees warmer in the evening. Depending on the food, we recommend using tried and tested preservation methods: boiling, drying and pickling.

Provide a draught

Fans are available for just under 10 euros, which are connected via USB plugs - ideally via a battery bank on board. If conditions permit, the deck fans can be turned into the wind with the opening for fresh air supply. And when at anchor, the use of a windscoop is recommended: The bag catches the breeze and directs it through the hatch into the interior of the boat.

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Ice in an insulated container

In well-insulated containers, ice cubes for refreshing drinks can easily stay frosty for a day - even in the heat. However, ordinary insulated bottles are somewhat impractical due to their usually narrow necks. It is much easier with wide-necked insulated containers for food. Despite the now very effective insulation, make sure that the container is not exposed to direct sunlight.

Mobile air conditioning

The company Evapolar offers a mini "air conditioner" in cube form with a USB connection for around 240 euros. It works on the principle of evaporative cooling. A cartridge is continuously moistened with fresh water, which evaporates. The power consumption is said to be just 10 watts; connected to a battery bank, no fixed installation is required. Cooling is said to be sufficient for around three square metres. A replica is now also available for a tenth of the price.

Set up a shade centre

In the northern climes, permanently installed biminis are not common. But when the sun is sizzling mercilessly, shade still needs to be provided. So a temporary solution is needed.

  • Parasol: A visually unattractive but simple measure is to use a sunshade: it is quick to set up, easy and variable to align against the sun and inexpensive to purchase. Niro Petersen and Lanztec offer universal sunshade holders that can be attached to the winch. Alternatively, brackets for the railing can be used.
  • Awning: Awnings provide shade in the harbour or at anchor. The simplest designs are placed over the main boom and tensioned towards the railing. There are also triangular models specially designed to shade the foredeck and the "overhead", a kind of giant frisbee with a five-metre-long aluminium tent pole. But beware: waterproof materials, which are also supposed to keep out rain, are impermeable and lead to heat build-up underneath. As a makeshift solution, air-permeable fabrics can be used as awnings. However, such materials are generally not very resilient and: In most cases, they do not offer any protection against UV radiation.

Plan your route flexibly

Travelling during the hottest part of the day can be a pain, especially on downwind courses. This can be countered with an adapted itinerary. If the sailing schedule allows, an early departure may make it possible to be in cool rooms or on the beach during the critical phase. The same applies to a late departure in the evening. You can also generally avoid the worst of the heat. A Mediterranean cruise in midsummer, for example, can be a real heat ordeal. Perhaps the trip can be moved to the early or late season? Or to an area with a more pleasant climate?

Covering hatches

This measure is common practice in motorhomes: windows and hatches are covered with reflective film. It doesn't look pretty, but it works. And if such cloths are tailored to the skylights, the appearance does not suffer too much. If needed spontaneously, it is advisable to use a rescue blanket, which has also proved its worth with motorhome travellers. Reflective inserts are also available for use from the inside, but heat can build up between the window and the film.

Sleep better

  • On deck: If there is a pleasant breeze at night, it is easier to feel on deck than in the bunk - especially as the heat below deck dissipates only slowly. This is why an open-air sleeping area may not be as comfortable as a bunk, but it is more bearable
  • Cooling mats: This unusual tip comes from skippers who have been travelling in very hot areas. The cooling mats are actually intended for pets, but an XL model for large dogs (around 80 euros) is actually used by some people, and some even swear by it.
  • Do not cook: If possible, you should avoid using the cooker immediately before going to bed. This is because the burner not only heats up the cooking pot, but also the surrounding area, which is already warm in this case.

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