Sometimes, you just got to bail. Whether a wave isn't working for you and you want to stay outside to line up for a new set, or there's an obstacle on your line you need to maneuver to avoid, there comes a time when you need to know how to cut a ride short safely and fluidly.

Kicking out of a wave is a surfer's get-out-of-jail-free card. An intermediate surfer in chest to head-high surf can pull off a kick out with confidence, but things get a little tricky in really big surf. Here, when things get iffy, you can still kick out, but it bears considering a few important variables.
Firstly, you need to be at or over the lip in order to kick out successfully and propel yourself to the outside of the break. On big waves, this could potentially mean a lot more distance to cover between where you are when you realise you have to bail and where you need to be to make it happen.
You can't always ensure a smooth glide to the natural end of your wave before kicking out. Sometimes, as in the case of someone dropping in on you, you have to make the decision soon after committing to the ride.

Note: This is why it's so important to follow rules of surf etiquette. Never drop in on someone so long as you can help it. Doing so - especially in large surf - could force the other surfer into a difficult kick out situation, likely resulting in big wipeouts and injuries.

If this happens to you, there are a few things you can do. Although complicated and risky, it's better to have a go-to skill than no plan at all. If you've just dropped in, you might be close enough to make a sharp correction and hop back over the top of the wave, but more than likely, you'll need to follow the drop to the bottom, carve a bottom turn and pump back toward the lip.

It's even better if you're already in the pocket when you make the choice to kick out, and here, speed and good aim are your two best assets. Bend low and pump as much as you can, following your line to the nearest exit spot on the lip.

Secondly, depending on the nature of the big wave, there could be a fairly deep trough into which you'll be leaping. Be aware of any waves rolling in after it and make sure you don't inadvertently get caught inside. Of course, once over, get back on board and begin paddling for the outside right away.
Finally, kicking out in big waves pretty often involves some air time. You'll be able to tell from the speed at which you approach the lip whether you're going to take air, so plan accordingly.

As you close in on the lip, crouch low and lean your shoulders in the direction you want to go. As you mount the lip, grab a rail and scoop your heels down and out in a forward, clockwise motion. Exit your air by diving off-side or forward, and let momentum take care of the rest.