A heatwave forecast to raise temperatures across the UK this weekend and into next week could bring misery for boaters.

The ‘Spanish Plume’, a draft of hot air sucked up from Spain and North Africa by a gap between high pressure over northern Europe and low pressure over the Atlantic, could push temperatures above 31C and bring with it heavy showers and thunderstorms, particularly in the North West.

Potential risks to boats include worn mooring lines, blocked cockpit drains, torn covers or canopies, and submerged heaters or de humidifiers.

Wooden boats could be particularly at risk the deck and hull seams sitting above the waterline can open up in dry weather. A sudden heavy downpour may then be enough to put open seams under the water, with potentially devastating consequences.

Furthermore, open craft boats which rely on automatic bilge pumps could be at risk if the pump or battery fails in heavy rain, so these shouldn’t be depended upon.

Ribs with large outboard motors are at risk of sinking or total immersion of the outboard, should the transom get dangerously close to the waterline.

Yachts with keel-stepped masts normally take water onboard during heavy rain. Aside from the cosmetic damage caused by excessive water in the bilge, if the boat has not been checked for many months the gradual build up of water can damage low lying machinery or electrics. This can lead to sinking, if open skin fittings, water outlets, or anti-siphon loops go below the waterline.

Moreover, motorboats are often damaged when the exhaust outlets are submerged under the waterline and leak into the boat or engine bay, or when cockpit lockers and engine covers send water into the bilges.

Insurance company Navigators & General is urging boatowners to be vigilant during the severe weather or risk problems on making any insurance claims.

“In terms of insurance, it’s not straightforward,” said a spokesman for N & G. “Policies generally exclude claims due to gradual ingress of water into a boat plus motors and electrical machinery are normally specifically excluded.

“Particular attention will be paid to how the owner has maintained or safeguarded the vessel. Therefore, the policy holder, or someone acting on their behalf, has an obligation to regularly check the vessel and take action should she be at risk.”

Check the forecast at BBC Weather.