Ocean, ships can easily exceed the range of turrets by going above/below them...it is not at all hard to fortify a planet such that no ship could avoid turrets in the 2D plane, but ships could easily avoid them if they just went up or down....this is because ships can go far above or below a planet (farther than they can go in the 2D plane due to the size of the gravity well) and directly above/below a region that turrets can't even be built in (since you can't build structures inside planets)...
Even if turrets could hit all targets, that doesn't change the fact PJIs and mines can be entirely avoided, and there is nothing you can do about that...
Furthermore, even if you do build an SB using the z-axis, and say build that SB above the planet, that leaves the entire 2D plane and everything below the planet well outside the range of the SB...in essence, the SB can cover a significant portion of the 2D plane, but it cannot cover even close to a significant portion of the 3D space around a planet...that TEC/Advent SBs can't shoot directly up or down only makes matters worse...
