Top Tips – Mainsail and Rig Trim

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Top tips on sailing well with an in-mast furling mainsail and how to tune your rig for best performance. Sail trim expert and prize-winning racing sailor, Karl-Otto Book of Elvstrǿm Sails, joins us aboard our new Southerly 480 for a test sail in the Strait of Gibraltar at the entrance to the Mediterranean Sea to demonstrate how to best use our new Epex sails and in-mast furling mainsail. This is the first in an on-going series of videos about trimming your sails for cruising.


Principal photography by Paul and Sheryl Shard.


Paul and Sheryl Shard are award-winning travel documentary filmmakers and videographers and have been cruising internationally since 1989 documenting their global adventures for television, in books and sailing publications. They are the producers and presenters of the Distant Shores sailing adventure TV series which is broadcast to 42 million households in 24 languages around the world. Through their TV programs, YouTube videos, articles/blogs and popular cruising seminars the Shards help anyone dreaming of setting sail to get out on the water and experience their own adventure safely and comfortably.


Featured in this video:
Elvstrøm Sails:
Epex Sail Technology:
Seldén Mast:
Brunton’s Propellers:
Navionics Charts:
Highfield Classic Inflatable:
Discovery Yachts Group / Southerly Yachts:
Marina Bay/Ocean Village, Gibraltar:
Visit Gibraltar:


Get an introduction to the cruising life and join us on a leg of our upcoming Around the World voyage. Learn more about our Sail Away Weeks here:


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All 130 full half-hour episodes of the Distant Shores Sailing Adventure TV series are available as a collectors set as HD downloads and also on DVD through the Distant Shores website. The Distant Shores DVD Super Pack box set is perfect for binge-watching and makes a great gift for the sailor in your life! Info and order here:


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Thank you for watching!

Sheryl and Paul


About the author


  • Wow, he certainly knew what he was talking about, brilliantly informative. Thank you for very interesting film .

  • Great video. Thanks. I learnt so much while getting a great closeup of your new cockpit arch which I’m quite excited about and it helps me determine how to build that feature into our S135. A question for your Elvstrom expert, I have seen in a video on a HR 54 vertical expanded pockets in the leading edge of the jib. Why are they there and what do they do? Have you used your swing keel much yet?

  • So very beautiful and informative 🙂 All in one great video. Thanks again! We also went for the comfort sail and was never in a hurry. Afterfall, it's sailing not jet racing and we always got enough rough sailing when bad weather hit.

  • Really like the look of the composite sails upwind. Were you guys a little uncomfortable at 20 degrees? it certainly looked fast 🙂

  • You guys offer the best seamanship commentary of all the sailing channels. Love it! Enjoy your new boat and keep up the good work!

  • Nice video and graphics👍 I was hoping you would of zoomed into the leach line the sailmaker was talking about. Curious minds

  • Great show! Always interested in expert technical advice and nothing is more important than proper sail trim. Beautiful lines on your new boat, she looks fast and most importantly comfortable.

  • Nice video, thanks for sharing. We have the same issue with getting up to the leech tensioner, tied an extension onto it so we don’t have to stand on the cockpit table to set it. Happy and safe journey on your upcoming crossing.

  • Very interesting video.
    Do you think it is allowed to manipulate quite often the aft rig to bend aft the mast since I didn’t touch on my boat (I thought it is a rigger specialist work)
    I have a furling main sail on my Bavaria 46 do you think it is possible to install a furling one with batten?

  • Excellent explanation and graphics. First time I have actually understood what happens when the bend of the mast is adjusted.

  • Another special video. I so like how you both combine information on where you are, with how to correctly adjust yours sails. Thank you again for sharing.

  • Very nice. The more wind you have the more everything is moving aft (mast top by tensioning the backstay and the genoa lead). At least this is how I remember it every time 😉

    BTW: very good graphics that makes it so clear what happens! Still images are never so explanatory.

  • Wow I have never heard of someone adjusting the backstay rigging on the fly. I thought it was just something you do when you install and do maintenance. But I mostly sail small boats > 20 feet

  • Great explanation!!! We are just finishing our first season in the Med. Still getting to know our best set up for sails and rigging. So this info is really helpful. Hope to see you out on the waters soon.

  • As usual very thorough explanation on adjusting the mainsail. Never understood why one would wanna bend the mast to adjust the sail. Thanks for sharing.

  • thankyou – a very informative video

    are you able to discuss pros and cons of inmast vs inboom furling and why you went with the former

  • Very Kool…have seen many folks sailing with the in mast reefing system. But never any explanation of how to use, trim & adjust everything.⛵️
    That may be that a lot of 'sailers' haven't taken the time to learn. 😂

  • Great to have the sail maker on board. I hope he got rid of that ugly hook on the mainsail leach at 2:00. Have fun with Ruby Rose! Cheers Warren

  • Our “new” boat has a Selden in-mast furler and we’ve only sailed her a few times as we’re a little intimidated by it. This video will be a huge help. Thank you.

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