Skip to main content

O-Puzzle Series – November 26, 202

O-Puzzle Series – November 26, 2025


Today’s task is based on the map used in my book Planning Reliable Routes, the second book in the Confident Orienteering series. This same map is featured in one of the examples and on the cover of the book.

Task: Find 5 errors in the index contours.

Note: When completing the task, keep in mind that index contour “A” is correct.


 

Explanation and Answers:
An index contour is shown for every fifth contour line. Its function is very important — index contours (thicker lines) help us better understand the overall shape of the terrain and the height of slopes. 


1. The contour of the hill is at the same level as contour "A".
2. The contour of the depression is two intervals higher than the contours at level "B".
3. The contour of the depression is at the same level as the contours at level "B".
4. Same as case 3.
5. The contour of the hill is only two intervals above the contours at level "B".

***

Make the most of the off-season between 2025 and 2026 — review your navigation system if you're not satisfied with its current quality.
The Confident Orienteering book series -  a systematic approach to minimising errors - will definitely help you with that.

The most detailed analysis of navigation in orienteering:

Book 1: Fundamentals — Understand the causes of mistakes and develop strategies to reduce them.
Book 2: Planning Reliable Routes — Learn how to plan routes that account for a wide range of potential errors.

Aleksandr Alekseyonk, November 26, 2025. 

Comments

Post a Comment

Popular posts from this blog

  Case Study #4 Case: You ran onto a narrow ride slightly below its end and are unsure which of several similar rides you are on.   Solution: In this situation, the relief profile can assist us. Even if the rides themselves appear similar, the relief profile along each ride differs , providing valuable clues for accurate positioning. This approach is discussed in Chapter 3 ( Using All the Indicators for Confident Positioning ) of the book Planning Reliable Routes . It demonstrates that relief can be used not only when we are uncertain about our current location , but also proactively during route planning . By analysing the map in advance, we can identify segments where linear features intersect with relief forms , creating distinct and easily recognisable points. These can serve as reliable positioning features . Additionally, flat areas and transitions between slopes and level terrain can also support effective location verification. (Example taken from my book Plann...
Post a Comment
Read more

New o-book is coming this fall!

  New O-Book Coming This Fall! Confident Orienteering: A Systematic Approach to Minimising Errors Book 1: Fundamentals was released in October 2023 and has already been translated into seven languages , alongside the original English edition. With 8 chapters and 140 pages, it introduced the core concepts of the author's navigation system — and I’m still amazed at how warmly it was received by orienteers around the world. 🌍 As we continued working on the next part of this practical guide, it became clear that the project had grown into something much bigger — not least because of the sheer number of examples and illustrations included throughout (around 250 in total!). To make the material easier to absorb, we’re now leaning towards splitting it into two volumes , each with its own clear focus. This isn’t a final decision yet, and even the titles below are working titles — but right now, this structure feels like the most reader-friendly option: 📖 Book 2 (working title...
Post a Comment
Read more

Book 2 Nears the Finish Line

  Book 2 Nears the Finish Line Editors Ross Barnett and Clive Allen are now in the final stage of polishing Confident Orienteering Book 2: Planning Reliable Routes . Ross has already done two full read-throughs, which put me on an emotional high – and it’s still going! Clive has started the final proofread before layout. My wife, Svetlana (the book designer), and I are wrapping up the explanatory graphics for the illustrations. The test readers have also finished reading all the chapters. I’ll share their feedback once we start the layout phase. If all goes well, in about two weeks we’ll begin laying out Book 2. The goal is to release it in late September or early October. Fingers crossed everything runs smoothly in these last weeks. Work on Book 3 (Routes executing) is also moving fast. Only two chapters are left – and then the whole Practical Guide  'Confident Orienteering: A Systematic Approach to Minimising Errors' will be complete.  Editing is already underway on...
Post a Comment
Read more