Efficient route planning is crucial in seafaring, where navigating requires consideration of various factors such as environmental conditions, vessel capabilities, safety, and arrival time constraints. While timely arrival is key to energy efficiency, prevailing strategy is getting near the destination as quickly as possible, anchoring or drifting until arrival conditions are met. Focusing on design factors for implementing arrival time (re)negotiation in onboard route (re)planning, we developed and tested two visual query interfaces for identifying arrival time windows under multiple constraints. Our first insights from this ongoing study are relevant for route planning in multi-objective optimization scenarios beyond the maritime context: (1) Stop dumbing it down—Query interfaces should not conceal too much of the inherent complexity. (2) Hitting the sweet spot of controllability is not (so much) a case of individual preferences. (3) Be realistic—Critical design challenges emerge only with a realistic or plausible fictitious scenario.