And hi again As I have mentioned I have very little experience with extended elevations, but taking your example as an opportunity to learn... The following excerpt from the Therion book suggests you may have made an error in input. Perhaps if you specify only one station it will work as you desire? "normal/reverse . extend given and following stations to the same/reverse direction as previous station. If two stations are given, direction is applied only to given shot. Bruce -----Original Message----- From: therion-bounces@speleo.sk [mailto:therion-bounces@speleo.sk] On Behalf Of John Pybus Sent: Tuesday, 24 February 2009 12:45 p.m. To: Therion List Subject: [Therion] Problem using extend command Hi, We're still working on our extended elevation, and have been having problems getting the centreline to work with extend configuration commands. We have found a number of occasions where an "extend reverse stationname" command reverses one leg at that point but doesn't apply to any folloeing legs. e.g. in a passage going 5 -> 6 -> 7 -> 8 -> 9 -> 10 extend reverse 7 gives: 5 -> 6 -> <- 7 8 -> 9 -> 10 when I would expect: 5 -> 6 -> <- 7 10 <- 9 <- 8 We've ended up having to add explicit extend right configuration for station 7, then station 8 and station 9 etc. We've tried to pare down our survey to one example of this in the attached file (julagua-elev_testcase.th) There are also several other examples where this occurs commented out. Any chance of fixing this? Cheers, John & Hilary