Make the most of natural air circulation
The first and simplest method is based on creating air currents. Whether stationary or at anchor, it's essential to keep the air inlet and outlet points as open as possible. Installing a canvas windsock on the foredeck hatch, facing into the wind, helps to force a flow of air inwards. Some yachtsmen also use modular canopies or biminis that channel the air while providing protection from the sun's direct rays. Electric fans, powered by the battery pack or a shore power supply, can be used to reinforce ventilation.
Creating shade and limiting heat gain
Reducing exposure to the sun's rays is essential. A sun awning is an essential piece of equipment, but you can also hang a light white canvas over the deck, or even the entire length of the coachroof, to reduce the interior temperature. In the hottest ports, some people don't hesitate to use shiny survival blankets to reflect some of the sun's rays. Inside, closing south-facing portholes and using light-colored curtains also help to limit overheating.
The evaporation trick
Water remains an excellent means of cooling the atmosphere on board by evaporation. Regularly wetting the deck with âeuros of seawater, so as not to draw on the âeuros reserves, helps to lower the ambient temperature. A damp towel hung in the companionway, a wet blanket on the roof, or even a simple basin of water in front of a fan can help cool the ambient air. The principle is simple: as water evaporates, it carries away heat.
Optimizing existing equipment
Some equipment can be put to good use. A well-stocked fridge with bottles of ice water becomes a reserve of freshness. By placing these bottles in front of a small fan, you can create a makeshift cool ventilation system. It's also worth thinking about insulation: good thermal insulation under the roof or deck significantly improves comfort on board. Well-insulated âeuros units, such as some boats with injected âeuros foam, retain their interior temperature better.
Adopt an adapted lifestyle
Finally, you need to adapt your daily routine to the heat. It's best to avoid the hottest hours in the cabin, preferring early morning or late evening activities. Sailing, wind permitting, remains the best way to escape the port heat. And for the lucky ones, head for temperate zones: the Atlantic coasts, the Bay of Biscay or the Iroise Sea sometimes offer a real thermal respite.
In short, heatwaves on board are not inevitable. With a little organization, some simple equipment and good seamanship, it's possible to maintain a minimum of comfort, even without air conditioning.
