Reading The Telltales

Book Extract

Telltales are indispensable for providing a visual indication of how well the sail is trimmed whilst you’re sailing close-hauled and reaching, i.e. when the sail is acting as an aerofoil rather than an air dam. Telltales can immediately tell you whether you’re over, under or correctly trimmed, and whether the sail’s twist is correct. Note that they don’t tell you whether the sail is under or over powered.

There are two types of telltale that can be attached to a mainsail: leech telltales and draft telltales. It’s preferable to have both types attached.

Leech Telltales
As their name suggests, leech telltales are attached to the sail’s leech. Leech telltales work by showing whether the sail is over trimmed or under trimmed as follows:

• If the sail is over trimmed, the telltales will wrap around the outside of the sail.
• If the sail is under trimmed, the telltales will stall or wrap around the inside of the sail.
• If the sail is trimmed correctly, the telltales will flow out evenly.

The telltales also provide an indication of whether the twist is correct. Assuming that the bottom and middle leech telltales are flying:

• If there’s not enough twist, the top telltales will wrap around the outside of the sail.
• If there’s too much twist, the top telltales will stall or wrap around the inside of the sail.
• If the twist in the sail is correct, the top telltales will flow out evenly for roughly 80 % of the time.

Draft Telltales
Draft telltales provide a better level of visibility into where exactly the air is flowing on the sail.

• If the sail is over trimmed, the outside telltales will lift and stall whilst the inside telltales fly.
• If the sail is under trimmed, the inside telltales will lift or stall whilst the outside telltales fly.
• If the sail is trimmed correctly, both the inside and outside the telltales will fly.

As we saw above for leech telltales, the draft telltales also provide an indication of whether the twist is correct. Assuming that the bottom and middle inside and outside draft telltales are flying:

• If there’s not enough twist, the top outside telltales will lift and stall whilst the inside telltales fly.
• If there’s too much twist, the top inside telltales will lift or stall whilst the outside telltales fly.
• If the twist in the sail is correct, both the top inside and outside the telltales will fly.

 

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Mainsail Trimming is written by Felix Marks. Felix Marks is an enthusiastic sailor who has sailed British and Australian waters with a great understanding of sails.