Here's a V drive transmission:
Ignore the arrow in the right hand image, intended for another discussion.
The engine sits 'backwards' in the boat, the gearbox at the forward end, and the shaft exits the V drive under the engine.. Many such installs put the stuffing box and its gland/seal directly under the oil pan in an almost impossible-to-access place. A most compelling reason to install a dripless seal, as a spraying leaky gland can do nothing good for the pan.