Tom, The "adjustable boom height" is a downhaul. It is used to adjust the tension on the luff which, like the outhaul, controls the draft in the sail. In strong winds, more tension flattens, and depowers, the main sail. Use less tension in lighter winds to create more draft. Some classes use a Cunningham instead, which pulls down on a grommet in the sail instead of pulling down on the boom. In any case, always raise the main to the top. Rich Makela M-17 #233 - Harmony -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Tom Jenkins Sent: Saturday, August 06, 2011 12:36 PM To: For and about Montgomery Sailboats Subject: M_Boats: boom height Hello gang, My Montgomery 17 is the first boat I have had with adjustable boom height, and I am not sure how to get the best out of the feature. I have been running my boom 17" above the deck, which marginally reduces forward visibility and probably misses out on some wind (and makes installing a vang problematic), but there are fewer issues with the various ropes and wires rubbing at the masthead, and perhaps somewhat less healing moment. I can raise the boom as high as 28", and wonder if anyone out there runs it that high, and what the consequences are. I could go with a fixed gooseneck, but I would not know how best to locate it for a variety of conditions, whereas some of you have been successfully sailing these critters in all types of conditions for years and years. Anyway, comments about boom heights or actual measurements would be very helpful and greatly appreciated. Tom Jenkins M17 Scintilla, Hull 626 _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats When posting, remember that there is no privacy on the Internet!