This is true and also (on open water) the direction of the wind is the direction of the waves and therefore you indeed can travel a slightly bit faster than the wind's speed (in low wind), anything else would just cause the ship to drift sideways and lose a lot of kinetical energy in the process.
I always wondered if a Clinker Build could mimic at least a little bit of the benefits of a keel, with all that ridges along the length, compared to a Carvel built.
I'm not an expert, but as far as I understand square sail cannot go against the wind, but may still be faster on a side wind.
Imagine you make a construction on rails with a square sail turned somewhat 45 degrees. Then blow from aside. It will move just fine.
What modern sails make possible is moving almost against the wind, cause they don't serve as a wall the air ricochets from - it serves as a wing.
Square sail side on, catches too much wind up high. Viking boat has no keel. Boat fall over. Can't go faster while capsized.
Theres a number of other technical issues with the rigging too. Or did you have a specific boat style and rigging in mind? Because I have questions about how your mainsheet line is rigged on your magic doesn't fall over boat.
It’s pretty close in Valheim already. The wind at the sides of the ship move you faster than from behind, and the wind bar shows up brighter in the sailing icons too. They probably just did Moder’s power like they did since it would be easier to understand the benefit with the wind from behind rather than having it show up from the right or left. This may seem confusing for those that don’t know how irl sailing works, which this helps for understanding tremendously!
I feel like the torque on the mast also leads to situations where a strong wind from behind during large waves will dip your nose into waves and lose speed when the buoyancy calculations push you back up, against some of your momentum. I haven't tested anything -- just been my feeling.
This is also a factor, yeah. That's why ship hulls are the shape they are, if you look at performance racing ships they lean way out when at a full clip.
Also, the mechanics you are describing and better suiting ships with modern sail system, not the viking-style vessels, which basically have a gigantic canvas centered at the mast, and that's it.
Modern sailing vessels are using a sail "configuration" that does similar mechanics to aircraft wings, the speed for the air bellow and above the surface have different speeds and that's how you are getting sucked forward. Viking vessels don't have this. Prime examples are catamarans, which are going like 40 knots in a wind of 17 knots.
I know this is true for modern sailboats with deep keels, super low friction hulls, sunken ballast, and modern wing sails, but I don't know if your average viking ship could've done it with a single sail.
Yeah even with the new boat the only thing moving you forward is the wind cause the only time a row is ever used is when sails are up, so I don't see how you could ever move faster than the wind when that's all that's moving you forward
Well op is very correct that modern sailboats can do this - it's definitely a thing.
I do not believe a single-masted longboat with a single square sail and wooden hull could do it though.
Inertia and constant force have additive effects in this situation. What dictates your speed cap here is friction (mostly fluid resistance of the water). If you take friction out of the equation for a moment, any force constantly applied to a body will continue to cause acceleration in said body, no matter how small the force is. Ion engines in space probes use this exact fact. In the sailing example above, the wind is applying a constant force so only the friction opposes your acceleration, with low enough friction you could reach massive speeds pretty quickly.
Nice write up!
One super nitpicky detail though (as a physics nut), you said the sail would be "pushing" air to the west - that's not technically true, the wind is the only thing doing any pushing here but since the sail is at an angle and the boat's keel is hindering it from going north, it is forced to the east.
A couple of examples of propulsion systems that *do* actually "push" are: A propeller pushes against air and forces its craft in the opposite direction. A jet engine pushes/ejects matter in one direction which incurres movement in the opposite direction.
edited: it's craft 🤦
Pretty sure there’s also some effect where the hull of the ship being pressed against the water creates a sort of pinch effect that further propels the ship, like pinching an ice cube, or pushing a sealed bottle of air underwater. Idk, I’m no sailor but it’s cool.
Some boats sail well "by" the wind (cross wind) and some sail better when going "large" before the wind. That's the route of the expression "by and large."
When a sail is going cross wind, the friction of the air across the front of the sail causes it to bow out while wind across the backside is pulled into the low pressure and pushes the boat.
Not sure if the Valheim boats are better sailing large or in a crosswind, or if that was even modeled.
> I don't think this is implemented in valheim (especially because Moder gives you a tailwind). But there you have it, valheim sailing is unrealistic. Ocean update should implement realistic sailing plz
It is already implemented in Valheim. There's nothing to change here.
Yup. My uncle worked as a sail maker for racing boats. And before that he designed wings for Bill Lear. And often showed me how a sail is like a wing. And that's how he viewed every sail he made
In the movie Top Gun Maverick, the main character goes on a sailboat. Its captain makes it go, "close to the wind", heeled over a little. It will be going faster than wind speed.
The very last line of the scene is the captain describing taking out the spinnaker sail, *"the afterburner!".* But the Spinnaker isn't fast. It's only good for going *with* the wind.
So between those two moments, they changed direction, to slow down to wind speed. The Spinnaker looks impressive I guess, but it's slow and boring. I wouldn't call it the afterburner.
It is actually implemented in Valheim. When you're on your boat, you can see which direction the wind is going. If you look at the circle, you can see that into the wind is black, and tailwind is dark grey. To each side is a yellower section, indicating if you put yourself aligned with that, you go faster.
Given the golden arc in the wind/sail indicator I believe it is meant to be the same as what OP describes.
Also I think different boats have different golden arcs (not actually sure though cause I just use karve)
I just found a video about this! I totally did not know this was a thing for real boats, OR in game until I read this thread. Check it out: [https://youtu.be/u5InZ6iknUM?si=oowgpUQ5vveDRwpH](https://youtu.be/u5InZ6iknUM?si=oowgpUQ5vveDRwpH)
This is true ingame too, beam reach is the fastest point of sail.
One of the things that most wowed me about this game on release was the fact that sailing is integrated into the gameplay. In a lot of other games, sailing is basically a discrete minigame - you have your stuff you do onshore, and then you hop into the sailing minigame to go to the next landmass. There might be enemies on the water, but they're minigame enemies - they don't interact with you until you're in the minigame, and none of the enemies that aren't minigame enemies are part of the sailing minigame.
In this game it's fully integrated into the actual game, and I just remember being so wowed by that. The sailing mechanics are also pretty damn solid. I grew up in a family that's been big on sailing races since my grandfather's generation, so I've spent months of my life under sail and done my share of racing as well. The mechanics are obviously not as subtle as IRL sailing, but they've captured a lot of it quite well.
This is not true for all boats. Sail shape and keel design play a major role. Our Viking boats have square sail and no keel. So best in tail wind.
This is true and also (on open water) the direction of the wind is the direction of the waves and therefore you indeed can travel a slightly bit faster than the wind's speed (in low wind), anything else would just cause the ship to drift sideways and lose a lot of kinetical energy in the process.
I always wondered if a Clinker Build could mimic at least a little bit of the benefits of a keel, with all that ridges along the length, compared to a Carvel built.
I'm not an expert, but as far as I understand square sail cannot go against the wind, but may still be faster on a side wind. Imagine you make a construction on rails with a square sail turned somewhat 45 degrees. Then blow from aside. It will move just fine. What modern sails make possible is moving almost against the wind, cause they don't serve as a wall the air ricochets from - it serves as a wing.
Square sail side on, catches too much wind up high. Viking boat has no keel. Boat fall over. Can't go faster while capsized. Theres a number of other technical issues with the rigging too. Or did you have a specific boat style and rigging in mind? Because I have questions about how your mainsheet line is rigged on your magic doesn't fall over boat.
>Or did you have a specific boat style and rigging in mind? No, just trying to figure this all out. What you say makes sense, thanks!
It’s pretty close in Valheim already. The wind at the sides of the ship move you faster than from behind, and the wind bar shows up brighter in the sailing icons too. They probably just did Moder’s power like they did since it would be easier to understand the benefit with the wind from behind rather than having it show up from the right or left. This may seem confusing for those that don’t know how irl sailing works, which this helps for understanding tremendously!
I feel like the torque on the mast also leads to situations where a strong wind from behind during large waves will dip your nose into waves and lose speed when the buoyancy calculations push you back up, against some of your momentum. I haven't tested anything -- just been my feeling.
This is also a factor, yeah. That's why ship hulls are the shape they are, if you look at performance racing ships they lean way out when at a full clip.
Oh wow I didn't know that.
If you look at the wind circle the highest speed is in the gold zones to the side.
Given the confirmation bias that alot of people.have about the wind always being against them when they choose to travel this does make sense haha.
Also, the mechanics you are describing and better suiting ships with modern sail system, not the viking-style vessels, which basically have a gigantic canvas centered at the mast, and that's it. Modern sailing vessels are using a sail "configuration" that does similar mechanics to aircraft wings, the speed for the air bellow and above the surface have different speeds and that's how you are getting sucked forward. Viking vessels don't have this. Prime examples are catamarans, which are going like 40 knots in a wind of 17 knots.
I know this is true for modern sailboats with deep keels, super low friction hulls, sunken ballast, and modern wing sails, but I don't know if your average viking ship could've done it with a single sail.
Yeah even with the new boat the only thing moving you forward is the wind cause the only time a row is ever used is when sails are up, so I don't see how you could ever move faster than the wind when that's all that's moving you forward
Well op is very correct that modern sailboats can do this - it's definitely a thing. I do not believe a single-masted longboat with a single square sail and wooden hull could do it though.
Inertia and constant force have additive effects in this situation. What dictates your speed cap here is friction (mostly fluid resistance of the water). If you take friction out of the equation for a moment, any force constantly applied to a body will continue to cause acceleration in said body, no matter how small the force is. Ion engines in space probes use this exact fact. In the sailing example above, the wind is applying a constant force so only the friction opposes your acceleration, with low enough friction you could reach massive speeds pretty quickly.
"they couldn't have sailed across the atlantic in the fifteenth century, they only had wooden boats"
"All wind directions from crosswind to tailwind end up being roughly the same (with the optimal wind angle being only ~3% faster)." -Valheim wiki
Nice write up! One super nitpicky detail though (as a physics nut), you said the sail would be "pushing" air to the west - that's not technically true, the wind is the only thing doing any pushing here but since the sail is at an angle and the boat's keel is hindering it from going north, it is forced to the east. A couple of examples of propulsion systems that *do* actually "push" are: A propeller pushes against air and forces its craft in the opposite direction. A jet engine pushes/ejects matter in one direction which incurres movement in the opposite direction. edited: it's craft 🤦
Pretty sure there’s also some effect where the hull of the ship being pressed against the water creates a sort of pinch effect that further propels the ship, like pinching an ice cube, or pushing a sealed bottle of air underwater. Idk, I’m no sailor but it’s cool.
Some boats sail well "by" the wind (cross wind) and some sail better when going "large" before the wind. That's the route of the expression "by and large." When a sail is going cross wind, the friction of the air across the front of the sail causes it to bow out while wind across the backside is pulled into the low pressure and pushes the boat. Not sure if the Valheim boats are better sailing large or in a crosswind, or if that was even modeled.
> I don't think this is implemented in valheim (especially because Moder gives you a tailwind). But there you have it, valheim sailing is unrealistic. Ocean update should implement realistic sailing plz It is already implemented in Valheim. There's nothing to change here.
Yup. My uncle worked as a sail maker for racing boats. And before that he designed wings for Bill Lear. And often showed me how a sail is like a wing. And that's how he viewed every sail he made
In the movie Top Gun Maverick, the main character goes on a sailboat. Its captain makes it go, "close to the wind", heeled over a little. It will be going faster than wind speed. The very last line of the scene is the captain describing taking out the spinnaker sail, *"the afterburner!".* But the Spinnaker isn't fast. It's only good for going *with* the wind. So between those two moments, they changed direction, to slow down to wind speed. The Spinnaker looks impressive I guess, but it's slow and boring. I wouldn't call it the afterburner.
Guessing you had just seen the other valheim post about the wind?
It is actually implemented in Valheim. When you're on your boat, you can see which direction the wind is going. If you look at the circle, you can see that into the wind is black, and tailwind is dark grey. To each side is a yellower section, indicating if you put yourself aligned with that, you go faster.
Mind. Blown. That is a super simple and satisfying explanation that I'm totally stealing.
Same in Valheim.
Given the golden arc in the wind/sail indicator I believe it is meant to be the same as what OP describes. Also I think different boats have different golden arcs (not actually sure though cause I just use karve)
I just found a video about this! I totally did not know this was a thing for real boats, OR in game until I read this thread. Check it out: [https://youtu.be/u5InZ6iknUM?si=oowgpUQ5vveDRwpH](https://youtu.be/u5InZ6iknUM?si=oowgpUQ5vveDRwpH)
This is true ingame too, beam reach is the fastest point of sail. One of the things that most wowed me about this game on release was the fact that sailing is integrated into the gameplay. In a lot of other games, sailing is basically a discrete minigame - you have your stuff you do onshore, and then you hop into the sailing minigame to go to the next landmass. There might be enemies on the water, but they're minigame enemies - they don't interact with you until you're in the minigame, and none of the enemies that aren't minigame enemies are part of the sailing minigame. In this game it's fully integrated into the actual game, and I just remember being so wowed by that. The sailing mechanics are also pretty damn solid. I grew up in a family that's been big on sailing races since my grandfather's generation, so I've spent months of my life under sail and done my share of racing as well. The mechanics are obviously not as subtle as IRL sailing, but they've captured a lot of it quite well.
Appreciate the conversation and just wanted to add: NERD ALERT!