Rugby is a team sport whereas windsurfing is an individual sport.
Both sports need equipment.
Rugby is not expensive however, windsurfing is.
Also, rugby is played on a pitch while windsurfing is a water sport.
Compared to rugby, windsurfing is relatively safe.
In order to practice windsurfing you need to be a strong swimmer. On the contrary, in order to practice rugby you need to be violent.
In addition for rugby you need boots and a ball.
For both rugby and windsurfing you need to be fit.
As well as windsurfing for rugby you need equipment.
For windsurfing you need not only a board and a sail but also a wetsuit.
