A boat covers speed times hours, and everything else is detail. A sailboat averaging 5.5 knots makes 40 to 70 nautical miles in a comfortable daylight day and 120 to 150 running through the night. A displacement trawler at 8 knots covers 60 to 90 by daylight. A planing motorboat cruising 20 to 25 knots can log 150 to 250 with fuel stops. Here are the real numbers by boat type and the four things that decide where you land in the range.
- Distance = average speed x hours underway; averages are always lower than cruise speed.
- Sailboat daylight hop: 40-70 nm. Around the clock: 120-150 nm per 24 hours.
- Trawler at 8 kn: 60-90 nm daylight; motor yacht at 20-25 kn: 150-250 nm with fuel stops.
- Weather, daylight, fuel, and crew stamina set the real limit, not the brochure speed.
- Plan hops at 80 percent of your theoretical range and arrivals in daylight.
#The math, honestly
Take your realistic average speed, not your best speed, and multiply by hours you are willing to be underway. A 10-hour daylight day at a true 5.5-knot sailing average is 55 nautical miles. The same day at a trawler's 8 knots is 80. At 22 knots on a planing hull it is 220, if your fuel and your back allow it. Averages sag below cruise speed because of leaving the harbor, weather, current, and the last slow miles into the destination.
#By boat type
- Cruising sailboat (5-6.5 kn average): 40-70 nm in a daylight hop; 120-150 nm per 24 hours on passage, crew permitting.
- Displacement trawler (7-9 kn): 60-90 nm daylight; around 170-200 nm per 24 hours nonstop with autopilot and watches.
- Planing motorboat (18-28 kn): 150-250 nm in a long day, gated by fuel stops, sea state, and fatigue at speed.
- Sport catamaran or fast cruiser (8-10 kn sailing average): 70-100 nm daylight days are routine in trade-wind conditions.
#The four real limits
Daylight sets the comfortable window: most cruisers want the anchor down or the lines on before dark, which caps a no-night-sailing day at 10 to 12 hours. Weather sets the speed you actually average, and a foul current can quietly delete a knot or two for hours, which is why checking a weather window beats leaving on schedule. Fuel gates motorboats: range at cruise burn with a third in reserve is the honest ceiling, and our fuel calculator guide covers that math. And crew stamina is the limit nobody budgets: eight hours at planing speed in chop is physical work, and tired crews make poor decisions at exactly the wrong moment.
Plan hops at about 80 percent of what the math says you can do. The spare 20 percent absorbs a late start, a foul current, and a slow harbor entrance without turning arrival into a night landing at an unfamiliar dock.
Marine OS is marina management software, and the Marine OS route planner does this arithmetic per leg automatically: set your vessel's speed and fuel burn once, and every route shows distance, time underway, ETA, and fuel, with real port-to-port distances from the sea-route engine.
#Worked example
Miami to Nassau is about 192 nautical miles by the practical sea route (see our sea distance pages). For a 5.5-knot sailboat that is roughly 35 hours: one overnight passage or two days with a Bimini stop. A 22-knot motorboat does it in about 9 hours with a fuel plan. Same water, same distance, completely different day: the boat sets the plan.
Let the planner calculate every leg for you
Set your speed and burn rate in a vessel profile, drop the route, and read distance, ETA, and fuel per leg and for the whole trip.
#Frequently asked questions
Frequently asked questions
Know your true average, respect the four limits, and plan at 80 percent. The rest of the method lives in how to plan a boat route and the passage planning guide.
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