There's several types of long distance kayaking: Long distance races, expeditions, marathons and overnight trips - all need a level of preparedness beyond that of your afternoon paddle.
In long distance kayaking there are so many variations to the way you might pack, so here I'll cover the highlights for you, including the overnight trip.
For most people the overnight trip will be the longest they take, and gear is similar - you just won't need as much!
I'm assuming you've got all the basic shelter, safety and survival kit that it's recommended you take on kayaking trips, as well as your navigation aids, passage plan (float plan) kayak, paddle and appropriate kit to wear whilst paddling and self-rescue aids when paddling alone.
Your tent and sleeping system is somewhere you shouldn't skimp on either. Even though I recommend using a larger tent, it's not allways wise to carry a lot of your weight in just the tent.
My personal philosophy on packing is to keep it as light as possible, and in that I have a tent that weighs in at under 1.5 kilos, a sleeping bag that doesn't weigh much more and packs down to an incredibly small size, and a mattress that is very light - might even squeeze in a fold-down pillow.
Remember: A down sleeping bag is useless when it's wet where a synthetic one - as well as being smaller when packed - will also keep you warm when damp.
Food and Energy
When you're paddling a long way on a kayaking trip, you have to remember that the kayak goes nowhere unless you move it or the tide or current does.
Invariably, the tide and currents usually run in the opposite direction from the one you want to go in! So, it's up to you to move it and that means you're the system of propulsion, and that takes energy. Lots of energy!
With the calorie count being anywhere up to 10,000 - and usually more for an entire day (eight hours) - you need to ensure you have plenty of food, and to cut down on space and weight you need foods with high calorific values.
The next thing you need to consider is hydration. Now, I could say that you have to drink x litres per day, but let's face it, we're all different.
You should be able to tell if you are hydrating enough, but one thing is the same: You'll always need plenty of liquids, and more hot drinks in colder climates whilst you're paddling. But avoid diuretics - not only is stopping for a whizz a nuisance, it can lead to dehydration if the loss of liquid isn't replaced.
After that I'd think about some comfort; on long distance kayaking holidays even a small folding stool can make a huge difference in your morale during the day when you stop for lunch.
It means you don't have to look around for somewhere to sit, or have to plonk on the floor whilst sorting out your food and drinks.
And it gives you the chance to sit down without having your hips in an inverted position.
Add plenty of treats. I've paddled with people who take all sorts on longer trips, from strawberries and cream to chocolate brownies and cupcakes, and even a few mints to suck on after having salt water blown about your head all day make a refreshing treat.
And always pack a simple repair kit for your sleeping system.
Change of Clothing
After you've spent all day in your paddling gear, it's a relief to get changed for the night. Pack a change of clothes to swap in to before sorting your admin out, getting food and hot drinks down your neck and establishing your night time routine.
As it's not the end of the trip, you need to be well-rested to get up the next day - and put on hopefully dry (but usually wet) paddling gear to do it all over again.
Always try and take things that have two or more uses, have spares where you think you might need them, and use common sense whilst you're packing.
If in doubt, ask yourself: "Will I really need this"?
And last, and definitly not least, waterproof everything! Might sound patronising, but you need to be on the case here. Take a read of Mark Pawlak's piece on Exped Pack Liners for some great pointers that apply to most adventure sports.
Rich is paddling over 700 miles for Help For Heroes and The British Legion - follow his adventure with The Greenland Cowboys