How can I stay in shape for swimming while working in the Egyptian desert? Help!

Hi - I love reading the discussion forums, and have finally got up the nerve to join because I'm looking for suggestions on how to stay in shape when I can't swim. I spend about three months of the year working on archaeological sites - while there I can't swim (no pool) or even walk or run, as apart from actual excavation we must stay in a small compound under military guard. I hate losing my conditioning for swimming while on these projects; not only do I desperately miss swimming while in the field, I hate coming back unable to keep up with my normal lane mates. But I haven't found anything good to do to maintain it. This year I thought about taking my jump rope - but then remembered that only the floors of the teeny shared bedrooms are solid, all the rest is sand. ANY desert "cross-training" suggestions at all would so appreciated. Thanks in advance. Flots