Assume that you have a planet mostly covered in water (about 89% of the surface is water). There are a few connected continents in the middle of the planet. If the rotation of the planet is slow, say 200 Earth days for a full rotation, and is temperate in temperature, winds on the planet are extremely fast. Since the wind speeds might be too high for a regular human to survive without a spacesuit, how would you make the planet survivable?
The geography of the planet can be changed, like mountains, but the actual planetary characteristics cannot, such as the rotation. The problem I ran into with adding a ton of mountains is that it creates a rain shadow. I want the continents to be temperate with lots of rainfall, so that does not work. Furthermore, I do not know if the mountains would slowly erode away and lose effectiveness. Additionally, large technological structures are out of the question because the natives are at a Roman-esque time period.
Clarifications:
The planet must remain windy out in the ocean, I am only looking to reduce winds to survivable levels in the middle of the continents.
The islands up north preferably are windier than the mainlands, needing special protection, but still need to be liveable.
The planet in question also has two moons, creating huge tides.
Any help is appreciated, thanks!