In this episode, we will delve into the art of sail trimming when sailing downwind. Whether you’re a seasoned sailor or just beginning to explore the boating world, understanding the nuances of sail trim can significantly enhance your boat handling abilities. Join our expert team as we provide insights, tips, and techniques to help you optimise your downwind sailing experience. This demonstration was done on a Lagoon 42 but can be replicated on other model vessels. 

TELLTALES

Learning how to trim your sail is a crucial skill for any sailor. Luckily, there are some useful instruments that can help make the task a bit easier. These instruments, called telltails, are ribbons attached to the sail that indicate airflow over the front and back sides. Ideally, you want the telltails to be in a linear motion, indicating a smooth airflow around both sides of the sail. If they are not, it means the sail is inefficient and needs to be adjusted. 

JIB/ GENOA

When sailing downwind, the goal is to maximize the sail’s efficiency by allowing it to catch the wind while avoiding excessive flapping or luffing. Here’s how you can achieve the optimal trim:

1. Assess the wind angle: Determine the angle at which the wind is coming from behind you. This will influence the sail trim adjustments you need to make.
2. Reading the telltales: While downwind, the telltales might struggle to fly due to lower wind speeds. Instead, focus on observing their behavior. If the telltales on the back edge of the sail flutter or deviate from a linear horizontal position, the sail needs to be eased out. Conversely, if the telltales on the inside flutter or exhibit disturbed airflow, the sail should be pulled in.
3. Avoid excessive flapping: Without the use of the telltales you can ease out the sail until you reach a point where it starts flapping, then pull it in until the point at which it stops flapping. This indicates an appropriately set jib or Genoa for downwind sailing.