This is a tough one. If I were on a sinking ship in the North Atlantic. I assume these days, that a SOS signal would have been sent out and alerted the authorities. And presumably there are lifeboats and people to help you survive. Hopefully the weather is clear. It may take a while for the ship to sink.

In the Sahara, nobody is going to even know or even look for you. Especially if you just drove out there all alone and your car broke down. On the other hand, you do have a few days to live before dying of dehydration. And if you did leave word back home that you are going to be crossing the Sahara, hopefully they would send out a search party for you in time. Maybe it is possible to find a cactus or two for water. If you just parachuted into the middle of the Sahara, hopefully you sent out a Mayday before making the jump, giving out your coordinates. Hmmm..

They say the Sahara is very beautiful, and I've never been there, so I think I will go and die in the Sahara.

duenhsiyen

I would rather be on that sinking ship for many reasons, not that I would really want to be in either of these cases. Hopefully the water isn't to cold that day. Personaly I would be to scared to get on a huge boat if there weren't enough of those little backup saftey boats or rafts. The advantage to be on water vs stuck in the dessert is that there is plenty of water to drink, eventhough it wouldn't be safe, I would still end up drinking it if it wasn't full of oil. I would probably try to catch a fish or two if possible. Another advantage is that I wouldn't be alone, and we would be on a specific route so it wouldn't be hard for another boat to come rescue us. In the dessert you could wonder for days and never be found, same is true for the water, but I think my survival chances would be greater.