Overland movement rates

[CoI]

My players are about to do some travel via ship so I've been going over the rules, and they seem a bit off. A sailing ship moves slower than a warship? And a galley is apparently the fastest ship ever? With that in mind I did some math and got even more confused. A ship that has a movement speed of 90, and let's assume that 90 is its max per round, should he doing approximately 10.2 miles an hour. And according to the overland movement rates that sailing ship goes 24 hours a day. Yet it moves 2.5 miles an hour, and 48 miles a day? Can someone explain this to me?

[Daw]

OK, historically the fastest sailing ships were the Clippers, which would leave a galley in their wakes. Their best times came out to about 18 knots, averaging about 8, since wind and currents weren't always on your side. Unsustained speeds of up to 30 knots were supposedly reached.

Galleys are going to have much slower top ends, they are fatter and have MUCH less sail area. A sustained speed of 10 mph is impressive, but then the Clipper captains didn't have wind spells.

Remember, this world completely changed with the advent of powered ships.

If it helps:
SPEED CONVERSIONS - KNOTS, MPH, KPH
Knots. MPH KPH
1 1.152 1.85
2 2.303 3.70
3 3.445 5.55
4 4.606 7.41
5 5.758 9.26
6 6.909 11.13
7 8.061 12.98
8 9.212 14.83
9 10.364 16.68
10 11.515 18.55

[Chemlak]

A few of your numbers are confused, but a sailing ship does 2 mph or 48 miles a day according to the CRB. If we snag Ultimate Combat's vehicle rules, we get this:

Maximum Speed 180 ft. (current) or 60 ft. (muscle); Acceleration 30 ft. (current) or 15 ft. (muscle)

But the important thing to remember is that the CRB info doesn't care about wind direction, currents, or any of the other things a sailing ship actually has to deal with, and simplifies all of that into a nice tidy figure of 2 mph.

[tonyz]

Paizo has no clue about ship propulsion systems.

Also, there is a difference between tactical movement (where galleys outpace sailing ships ridiculously, plus they can move in any direction they want regardless of the wind) and large-scale movement (where a sailing ship going with the trade winds can sail at 6-8 knots for at least 6-8 months, whereas the galley crew's arms fall off from exhaustion at 6-8 hours, and they all die of thirst in 6-8 days if they don't beach and drink some water)

Overland movement rates assume people travelling by foot for 8 hours (maybe 12) and sleeping for 8 hours. Sailing ships can go round-the-clock because their motive force doesn't suffer fatigue.

And this is even before we get into the difference that winds and currents can make.

But unless your players are Age of Sail aficianados, I recommend just assuming that the Paizo speeds are "average". Add/subtract a random factor based on the weather (and realize that unless the players can control the weather, sailing often involves really amazing amounts of maniacal patience as the winds do whatever they want, particularly if you're close to shore instead of in the open ocean.)

Recommending reading: the opening chapters of Samuel Eliot Morison's The European Discovery of America.

[CoI]

Even still, a warship shouldn't be faster than a sailing ship long term. I think if nothing else I'll swap warship and sailing ship daily speeds. Maybe give it a small bonus due to favourable current on the trade route. Does that seem fair/not broken?

[Daw]

Actually, yes, a rowed warship will usually be faster, it will have sails that can be taken down before combat, at least Biremes and Triremes usually did. Yes the warship will be faster over time by a lot, rowers work when the winds don't. Life is not good for the rowers, but what can you say?

If you want them on a faster ship, make it magic, and expensive.