See related climbing gear:
You should watch over the tide of the sea that you will be landing on. On your first fall, it can still hurt if you came from high up. Be sure to fall on a good angle so as not to injure yourself.
For your safety, here are some guidelines that can help you have fun in Deep Water Soloing:
You have to be cautious when you try Deep Water Soloing. Sometimes, the water temperature would be too cold and it would be hard for you to breathe. You must be a really good swimmer so you can be strong enough to counteract the waves and swim to a safer place. Be aware of hypothermia, which is a very real risk in this type of activity.
There are a lot of things to keep in mind since Deep Water Soloing is a dangerous sport. But once you are into it, adrenaline rush will help you enjoy every climb and fall that you will experience.