• Mobile App For Android Now Online!

    Download it here. The app is searchable in the Google Play Store under Sailboat Owners.

    Sorry iPhone/iPad users, we are still waiting on Apple. :(

    Click the X in the upper right corner to make this go away


Jul 19, 2013
Pearson 31-2 Boston
@Don Guillette - Do you have suggested locations and how many on a Genoa and a Main? I have 3 on my Genoa, located at a point on the sail where there are "clear" windows. There are none in the bulk of the sail and I could see how more would tell you more info for sail trim. On the main I only have tell tails on the leech of the sail at points where there are loops at the battens. Seems it would really be useful to have some on the face of the main in the belly at different heights and possible further aft between the belly and the leech.

I have your book and trim guide sheets but they are on the boat and am away from there right now. I have the genoa out for inspection and some restitching and it would be a good time to add them. I can do the main as I hoist it on a calm day.
The luff of the jib and the leech of the main are the key points, the belly of the main is useful that's about it. There's a good discussion of telltale use in
May 17, 2004
Other Catalina 30 Tucson, AZ
Over the years a number of sailors I've spoken to have minimize the use of telltales. If I'm on their boat during the discussion the next things I look at at is their outhaul and jib fairleads to see if they are functioning -- on older Catalina's most times neither of those are working either.

There is so much to these little pieces of plastic film or yarn that it took me 5 pages to cover it all and I'm not sure I did so. If you were using a highlighter all 5 pages would be yellow!!

The common attachment points for the JIB are at 25%, 50% and 75% and on both sides about 12" back from the luff. The most important set to watch on the jib are the MIDDLE. The attachment points on the leech of MAINSAIL are similar to the jib. You can use the battens as a guide. The most important mainsail telltale to watch is the TOP.

In my opinion that's the basic and minimum set up for the cruising sailor. "since there's no difference between cruising trim and racing trim. There's only a right way and a wrong way to trim your sail" - Dennis Connor's words not mine - I added a few more telltales. I attached a set to the middle of the mainsail about 1/3 back from the luff. I added one to each shroud. When I was demonstrating the effect of wind on the sails (attached flow) to beginners the extra telltales made the understanding so much easier for them because they could see it. As danstanford pointed out the America Cup boats have telltales all over the mainsail..

Over the Xmas holiday I was talking to a friend in Auckland, New Zealand - it's summer down there now. I met him by pure chance. We were on a cruise and the high point for me was to sail on the America Cup boats but the weather was too rough for them to go out. Anyway, he see's my wife and I wondering around the docks and we strike up a conversation. I love the folks and sailors from Australia and NZ - it only takes them 5 minutes and you are their best friend!! We saw his boat, he took us to his home to meet his family, we had dinner and spent the next day with them. Sorry to run on about that but it's winter and what else have you guys got to do but read a bit. Plus the covid knocked me for a loop and I had no interest in much of anything and I'm just now getting back into sail trim.

He's a cruiser like me but he wanted to squeeze a little more speed out of his Catalina 30. Here's what I suggested. To accelerate you need LIFT. Along with lift comes DRAG. If both telltales are streaming you're at the highest point of the lift/drag curve. Lift is highest but so is drag. To get a little more LIFT you want to push it a bit more. With both telltales streaming you want to get the windward telltale to FLIP. The "flip rate" in medium wind is about once every 3 seconds. In winds above 15 knots it's about once every 2 seconds.

Why is the top telltale on the mainsail the most important?
  • Like
Likes: jon hansen
May 25, 2012
john alden caravelle 42 sturgeon bay, wis
top telltale ... this i do not know. will love to learn.

don, for me, this is the best discussion about sailing this year. thanks for starting it.

May 17, 2004
Other Catalina 30 Tucson, AZ
I just received a Email from a beginner sailor asking what's twist? Others may have the same question.

I could provide the definition but it's better to show it. Form your right hand as if you were going to salute. What you're looking at is a flat sail with no power and no twist. Now turn your fingers ONLY slowly to the right. What your doing is inducing twist as the top of your hand (sail) is opening up and spilling air thus depowering the sail. Turn your fingers to the left to power up the sail. Eliminating twist in itself will not power up the sail. You have to factor in DRAFT DEPTH at the same time. Look at the salute again. Start to cup your hand. What you're doing is inducing belly or draft depth. Draft depth is your accelerator. You're not done yet - there are 2 more things you have to factor in for your main & jib to function at 100% and that's ANGLE OF ATTACK and DRAFT POSITION. What's draft position? Back to the salute. Cup you hand and imagine a line running from top to bottom across your palm at the deepest part of you cupped hand. As you open and close your hand the deepest part changes and that line moves back and forth. That's draft position.

Like a dance, all 4 elements have to function together at a particular individual setting for each point of sail and wind condition.
  • Helpful
Likes: Ward H
Jul 22, 2013
Com-Pac Horizon Cat Holland
Ship Mates: 2021 has got to be a better year. Nothing could be worse than last year.

The community we live in (4500 homes) is working with the state of AZ to distribute the vaccine and my wife and I received the first dose on 1/23/21. The vaccine is a tremendous step in the right direction to beating Covid. Even though we get our flu shots each year sometimes I get a touch of the flu but I'm able to shake it off in about 3 days. In mid February, 2020 I had all the Covid symptoms but our doctor told me it was the flu. If it was the flu I've have never been that sick in my entire life and it lasted for over 10 days. I didn't go to the hospital because that's where all the sick people were and they weren't admitting anyone anyway. I survived but Covid takes a lot out of you and it takes a lot of time to fully recover.

Enough about Covid - lets talk about telltales. Telltales are absolutely the most important sail trim indicator on the boat. No non-electronic devise has been developed that approaches the sensitivity and effectiveness of telltales on the mainsail and jib. Sadly, a majority of sailors do not have telltales attached to their sails. I feel they are so important that I devote 5 pages to them in my book THE SAIL TRIM USERS GUIDE. Telltales are the first thing I look for on any boat I go on. I even carry a extra set with me in the event the boat is lacking telltales Any conversation I have with sailors regarding sail trims starts with the question "do you have telltales?". I don't know how anyone can trim their sails to 100% efficiency without them - I can't and I know what I'm looking for!!

Telltales not only indicate the direction of the wind but how the wind is moving over the sails. On a masthead rig, the jib is the engine - on a fractional rig it's the mainsail. Telltales will indicate if the wind is flowing evenly over both sides of the sail. If one side is flopping around it creates a sail trim problem that needs to be corrected by either changing course or or trimming a jib sheet. The course change or jib sheet trim will depend on which telltale is flopping.

There's so much extra you can do with your telltales once you understand what they are telling you. Such as are you sailing too low or high plus they can indicate a full speed setting, extra pointing and extra power settings..

In my opinion "telltales are absolutely the most important sail trim indicator on the boat".

Stay safe and the sailing season is just around the corner.