Passage Summary: These new ships are fast but expensive to run. Since jet planes succeeded by being fast despite being expensive, these ships will probably succeed too.

Conclusion: Semiplaning monohulls will likely be profitable.

Reasoning: Although they are more expensive to operate than traditional ships, they offer speed and reliability, which allowed jet airplanes to be profitable despite their higher costs.

Analysis: The statement about high transportation costs serves as a 'counter-premise' or a concession. The engineer acknowledges a significant disadvantage of the monohulls to show they are being objective, but then introduces the jet airplane analogy to argue that this disadvantage can be overcome. When identifying the role, look for an answer that describes it as a potential obstacle or a drawback that the argument eventually dismisses by comparing it to a successful historical example.