Plate Tectonics: Is it possible to have an ocean-continent divergent boundary I am procedurally generating planets for an open world space sandbox game. I am using a rough simulation of tectonic plates to create mountain ranges and other geological features.

A planet surface consists of several plates, which consists of tiles. The continental plates are randomly generated, with random initial elevation and drift velocities assigned.

Tile elevations are generated by multiplying an envelope ( e^{ -d^2 } ) with a function for different types of plate boundaries and relative drift velocities.

For the sake of realism, is it possible to have a land-ocean divergent plate boundary? I could not find anything online. There also doesn't seem to be any examples on Earth from what I could find. Is it safe to assume that divergent boundaries only occur between land-land and ocean-ocean plate boundaries?

Update

Here is a rendering from the project. Red and green lines depict convergent boundaries. Land-land convergent boundaries produce mountains. Land-sea or sea-sea boundaries produces subduction zones. Blue lines denote a divergent boundary.



I'm going to change the simulation so that divergent boundaries happen only at land-land and ocean-ocean boundaries.

Sorry for my ignorance about geology. I know this is a crude way to simulate plate tectonics.
The oceanic plates are themselves formed from the divergent boundary, so probably not. Even if a new rifting occurred exactly at the boundary, the result would eventually be that the ocean floor surrounds the divergent boundary. 

A very simplified model of an ocean would have a divergent boundary in the middle. This oceanic spreading center might have basaltic volcanic islands along it, and two mirrored plates on each sides, pushing towards neighboring continental or oceanic plates. 



I'm trying to think about any oddity that would fit your description, but can't really come up with a good example. Locally you might have the conditions in triple junctions eg. at Afar Triangle. Somehow, it could also describe parts of New Zealand and eastern Mediterranean, but it's very complex areas with more parameters controlling the rifting. 

Earth is not controlled by any simple equation, its formed by 4.56 billion years of interaction between rocks, magma, life, atmosphere and even astronomic influence, so I'm not sure that divergent boundary never occurred between existing continental and oceanic plates, but at least it's very uncommon and couldn't last long. 

A way to understand plate tectonics better, and maybe even a good inspiration for world building games, is to have a look at the (free) program Gplates that is used by students and scientists to simulate tectonic history. Don't worry about your ignorance, interest is more important than knowledge. The game might be a good inspiration for someone to learn more about something really awesome.