I am not a speed kayaker or a daredevil or a showoff. I am into distance kayaking, going places and doing things. For me, the focus is on being able to GET to where I want to go, not to be the first person to get there or the fastest person in a kayak. I don't succeed unless I actually make it there. And because of the way kayaking goes, you can't guarantee you'll make it anywhere: you need to also be able to make it back to where you started. So for me, the goal is to aim to be where I want to be with about 30-50% of my energy reserves still in place. I don't want to go to a place where I've had to spend 95% of my energy to get to: I want to go to a place that takes 50-60% of my energy, because then I know that I've got reserves to draw on if I need to do something hard, say if a wind comes up or if I have to abandon and return to base partway because something bad has happened.
This is also why I am a fan of doing kayaking in a double. With a double, you have buddy to help you all of the time. I'd say it's about a 25% energy savings to go out with a partner, and if for some reason something goes wrong with either of you, if both of you have been careful with your energy usage, even having just one of you as the "engine" will probably ensure you can make it back in.
Trying to use my body to conserve my energy is really important to me, because there is not much you can do if you just lose your ability to provide any momentum to a paddle. For me my big weakness is my arms: major usage of my arms to get forward motion going (or to stop motion: applying the brakes or doing a big turn really takes it out of my arms) will get me feeling worn out really quickly. So I try to avoid doing the big turns, or trying to paddle really fast, or bringing the boat to a fast and complete stop. Instead I try to have a very even paddle that seems to be generated with almost no effort, created from (imagine this) keeping the arms in a box with the paddle/torso at the top/bottom and then rotating the paddle by turning my torso. This means it's my core muscles that are doing most of the work, and I'm just sort of giving the paddle a little push with the bottom of the hand that's furthest away from the water rather than trying to do a pull motion with the hand that's nearest the water (where the paddle is going in). Somehow this all seems easier.
There's a final thing that tires me out: getting cold, or getting scared. Getting cold is caused by getting wet, mostly, for me: you can get soaked from getting water dropped in your kayak, but also getting in the ocean will get you wet, and even a warm ocean takes heat away from you as your body dries. This is where the magic fat layer really helps a lot: I can get awfully wet but still stay warmer than a skinny person. (And of course you want to dress right.)
Getting scared is another problem. For me, doing "capsize training" is really unpleasant because my body does not like being upside down in water with water coming in my nose and ears. So this will cause me to lose almost an hour of energy. Similarly if I accidentally capsize, this causes me to lose about an hour of paddling time, because even though I recover quickly (as in "get out of the water"), I'm demoralized and it's just damned unpleasant. And then of course I'm cold. So bah. Fortunately I've never been in a situation where I've been scared of being able to make a trip back: for me, the goal is to never go out on a day where that might be a problem and to quit early rather than find you've gone too far. And so far, I've been lucky. I've got a lot more to learn about reading the wind and the water and the weather, and understanding current and depth charts and how everything all interacts with wind direction, but this is where going with someone experienced with a locale will really, really help keep you safe.
Keep warm. Conserve energy. Plan ahead. Quit while you can. Kayak safely.
Anyway. That's probably it for me writing about kayaking for the next six months. My hope is that this was all interesting to some of you. And now for me, I have to figure out how to make the good feelings I had the last week last longer, and to figure out what they have to say about trying to make the rest of this year good for me given that I can't be doing this all of the time!