The bottle tube fly has been a fantastic innovation in recent years for salmon fishers in Scotland. The bottle tube is as the name would suggest is bottle shaped and usually quite small in size. The advantage of the bottle tube is that it is quite heavy and so will sink fast. Therefore,  if you are looking for a small fly to get down quickly in the water column then the bottle tube is perfect for the job. These flies can be effective during the summer months when often smaller flies can be the order of the day, especially when targeting summer salmon or grilse.