Say the deck is stacked.
I'm out in the country with an all-band QRP home-brew rig,
and an active antenna. Or say ship-wrecked and marooned on that desert island. The battery only has enough juice for say 1-min Tx, and 30-min Rx. The Sun is at the bottom of cycle so conditions may be bad.
I need to get that priority message out.
How do I find out what bands are open?
Just a quick note to the comments about the scenario being totally unrealistic. An amateur radio expedition from VU was caught unawares when that Boxing Day tsunami hit the Andaman Island chain in the Indian Ocean. Unlike a team that goes out after the event, when the expedition went out they didn't know what they were going to have to handle.