If you are trying to instantly get as far as you can from the point of entry, here is my SOP for entering when shore diving from lava in Hawaii:
1. Inflate your BCD well.
1b. burp the air out of your drysuit
2. Step on the edge and turn your back to the sea.
3. Bend your knees.
4. Wait for the wave to come. Make sure there's nobody in your way.
5. Holding your mask, as you do in GS, fell back and simultaneously push hard with your legs.
The outgoing wave and your push take you away which is quite handy if there is some surf. This kind of entry also protects your camera from being hit against the water since it's the tank and your back that take the brunt of the contact.
I did not practice this entry from boats but I imagine this could be useful sometimes, especially, since most boats have something you can hold on to. And while you can slip doing a forward jump, you can't slip when pushing away.