The most valuable subsurface team member is:
The people of the island of Needreba have had a vision that they will be incredibly wealthy if they drill for oil. They have all the technology but none of the skills. A team of mercenary Geoscientists is assembled to help them, but the only transport available to get to the island is a hot air balloon. Due to technical difficulties the balloon is going down, and in order to stay aloft long enough to reach the island "someone" is going to have to jump overboard.
The islanders do not know where the oil is, only that it is somewhere under the island. They worship the great Money God, and if the project fails are likely to take terrible revenge on the remaining team member!
Each speaker is initially given 3-5 minutes to advocate their discipline. At the end of the round the audience is invited to vote, and the two lowest votes "goes for a swim".
The remainder then have a further 2 minutes to plead for their cause, before a further vote is taken and another Geoscientist is ejected.
The final two then have a final two minutes before the last vote. The island is then reached, the well drilled, and much wine will be drunk.