To unlock the Sword Surfer trophy in Metaphor: ReFantazio, follow these detailed steps:

### Step-by-Step Instructions

1. **Understand the Achievement Requirement**
– The Sword Surfer achievement requires you to travel a significant distance while blade-riding. There is no in-game indicator to track your progress, so you’ll need to keep track manually or use a method to ensure continuous blade-riding.

2. **Unlock Blade Riding**
– Blade riding is unlocked as soon as you begin the first stretch of free time in Grand Trad. This is where you start working on the achievement.

3. **Choose Optimal Locations**
– To maximize your distance traveled while sword surfing, use locations with minimal foot traffic. Some recommended locations include:
– **Grand Trad – Regalith Grand Cathedral**: This main plaza offers a large loop with little foot traffic, making it easy to surf around and get good mileage.
– **Brilehaven – Merchant’s Bazaar**: The street through the Merchant’s Bazaar to the podium has little foot traffic, allowing you to loop around and travel far distances quickly.

4. **Use Fast Travel Strategically**
– While fast travel can be convenient, it might not always help with this achievement. Instead, use it strategically to get to these locations and then start sword surfing.

5. **Implement the “Elastic Band Method”**
– If you find it difficult to maintain continuous movement, you can use the “elastic band method”:
– Place your controller on a flat surface with the left and right sticks in opposite directions. This will keep your character moving in circles, helping you maintain blade-riding without much effort.

6. **Grind if Necessary**
– If you’re not getting the achievement despite trying, it might be bugged. In such cases, try shutting down your system completely and restarting it. This can sometimes resolve the issue.

7. **Continue Playing**
– Even if you’ve been playing for a long time without getting the achievement, continue playing while sword surfing whenever possible. Some players have reported getting the achievement after some time not actively trying for it.

### Additional Tips

– **No Tracking Mechanism**: There is no in-game tracking mechanism for this achievement, so you’ll need to keep track of your progress manually or use the methods mentioned above.
– **Time Commitment**: This achievement can take anywhere from five to thirty minutes to complete, depending on your playstyle and the method you use.

By following these steps and using the recommended locations and methods, you should be able to unlock the Sword Surfer trophy in Metaphor: ReFantazio.