move props towards the mid hull section?

I've occasionally wondered why not use a non-steering L or Z drive (depending on the engine, of course) transmission mounted flush to an normal keel? Or perchance within the keel fully bedded to help keep water away from its casing?

Except for a lack of apparent shaft angle it would look like a normal set up for an inboard. An "Un-pod" drive. Yes, there would be mechanical losses associated with gears or belts of the transmission but these could be offset by the better horizontal positioning of the shaft and prop.

 

Look the propeller placement of this 55 sailboat :

http://www.amel.fr/upload/amel_55/AMEL_55_-_standard_equipment_and_plans_-_January_2015.pdf

Interesting when using sails (propeller in the wake of the keel) . Don't know about efficiency when motoring. Steering efficiency for docking may also be a problem if no thruster. (this sailboat has retractable bow thruster).

 

Totally screwy idea: if steerable (a pod in the keel) how effective would it be to help the boat use her sails on the reach or close hauled?