auto divebombing is acutally pretty simple, I use it most of the time because I'm pretty lazy and don't wanna line up the manual.

Basically you hilight the bombers and right click on your target.
A red circle will appear around your target ship.
Your bombers will move towards it, and once overhead they will dive.
As they dive, spam the right mouse button and they will drop their bombs.

Now, I generally use manual divebombing to group my bombers for a more effective auto bomb. Meaning I launch them in reverse numerical order ( ...4,3,2,1) so they come out closer, and then set them to "manual bomb" a random spot in the water far away. This forces them to group tightly. Then I select a target and follow the steps above.

thanks for the tips. But should i press and hold right mouse button or just keep clicking it. and also does it matter where on the screen i right click? because I tried this once and they didnt drop any bombs.

Click on your target ship once to target it. Once your bombers are overhead, they will automatically dive. As they dive spam the right mouse button ON the target ship to drop them.

MULTI-CLICKING the mouse button