Any top tips for using a rowing machine to help with training during an extended period of none running due to injury?

I'm more interested in maintaining (or building) endurance stamina than speed per se, and hopefully keeping a climbing ability.

Is it just a case of clocking up a regular, daily, shed-load of kilometres on the machine?

Setting a high drag factor (no cross dressing jokes please ), or medium (water-like) resistance?

Any thoughts/experiences will be much appreciated.