Mark Harris vanquishes jellyfish and harnesses the elements in his hardware round-up

Timex Expedition E-Tide Watch
The tide is high and you're holding on, but for how long? A glance at your wrist will provide the answer, if you're wearing Timex's latest smarty-pants timepiece. The E-Tide can roughly predict tidal variations within a given time zone. For more accurate results, you can calibrate it for a high tide at a full moon. If it all goes horribly wrong on the high seas, you'll be pleased to hear that the waterproof E-Tide will keep on ticking even as your boat sinks up to 100m below the waves.
£114.99; 020-8326 6900;

HYmini Wind Generator
Britain is far from the sunniest country in the world but it does have the honour of being the windiest country in Europe. So ditch that solar charger and pick up this portable wind farm instead. Holding the HYmini for 20 minutes in a stiff (20mph) wind should generate enough energy, stored on an internal battery, for a four-minute phone call or 20 snaps on a digital camera. It comes with a USB port, lots of power adaptors and even a wall charger if you need an emergency boost. An optional bicycle mount (£10) makes it great for recharging gadgets while you're touring although, bizarrely, the HYmini isn't fully waterproof.
£40; 0800 288 8970;

Tomcat Tandem Inflatable Kayak
If you think inflatables begin and end with lilos, think again. Inflate this four-metre monster (sadly a pump is not included) and you'll have a two-man kayak complete with seats and footbraces. Its self-draining PVC shell is tough and stable enough to take to coastal waters and there's abrasion-resistant material at the prow for safe launching and beaching. In the unlikely event that you do suffer punctures from rocks, the inner tube is replaceable. The Tomcat packs down to fit easily into a car boot and weighs an airline-friendly 24kg for international jaunts.
£399; 01493 745192;

Stash Folding Cycle Helmet
What better to accompany your next two-wheeled adventure on a folding bicycle than a folding cycle helmet? This well-designed skid-lid is made from shock-absorbent, injection-moulded ABS polymer and meets all the necessary international safety standards. When you're not pulling wheelies in the skate park or careering down a mountainside, the Stash helmet folds (somewhat) neatly in on itself for easy storage in your hand luggage or even a car glove compartment. It's UK designed, too.
£50; 0870 745 200;

Portable UV Monitor
Whether you're relaxing on the beach at Bognor or scaling glaciers in the Antarctic, the sun is doing its best to toast you to a crisp. Hang this lightweight (78g) gizmo from your rucksack - or a kid's wrist - and it will gauge the temperature and how strong the sunlight is. Input your skin type and what factor sun cream you're wearing, and the monitor will display your personal safe exposure limit complete with countdown timer. It runs on a small watch battery and is sand-resistant and splashproof.
£25; 0844 800 1965;

Cavius Personal Alarm
Nervous parents of gap year travellers can allay (some of) their fears with a gift of this multi-functional alarm. Its piercing 130dB alarm can be activated at the push of a button to deter attackers or attract attention. Alternatively, the Cavius can be set to go off when its built-in motion sensor is disturbed, allowing backpackers to secure their hotel door or bags at the beach. Finally, an optical smoke detector provides a startling alert for hostel fires - or, hopefully, simply someone burning toast in the night. It runs from a single AA battery.
£40; 0870 748 9562;

Senz Stealth Mini Umbrella
Here's one umbrella that shouldn't fly under your radar. Unlike most brollies, which collapse into a tangle of metal spikes and flapping fabric under the lightest of breezes, the Stealth Mini can withstand gusts of up to Force 7 ("moderate gale"). As the wind picks up, it actually gets easier to hold, thanks to an aerodynamic profile that angles it into the wind instead of trying to wrest itself from your grasp. The asymmetrical design does look strange when folded but it's light enough, at just 285g. If you want to venture out in truly nasty weather, a larger version (425g) can resist winds of up to Force 11.
£34.95; 0844 922 1010;

LifeSystems Expedition Sun Protection
Jellyfish may not top most people's lists of holiday hazards but anyone who has been stung while swimming knows they can ruin a dip in the sea. The makers claim this sunscreen contains an extract of plankton capable of convincing jellyfish that you are a harmless, microscopic sea creature. The Lifesystems sun cream is available in a range of protective factors and is fully waterproof. Now you'll just need a whale-repellent cream to deter any plankton feeders in the vicinity...
From £9.99 to £11.99 0118 981 1433;

JCB Tough Phone
Ever get the urge to throw your phone against a brick wall? Now you can, without having to invent a story about a runaway bus for the insurance company. The Tough Phone has been designed to meet military specifications, enabling you to drop it onto solid concrete, drench it in water or drive over it in your car without causing any serious harm. It works from a chilly -20C to a sweltering +60C, is tri-band for use across much of the world and has decent battery life - although you'll hunt in vain for features such as a camera or MP3. The phone comes with an unconditional three-year guarantee.
£180, unlocked for any network;