Rocna // Sizing Guides
To choose the correctly sized Rocna, match your vessel’s length with the most appropriate displacement range, also bearing in mind conditions of intended use (if in doubt, give preference to the larger anchor model).
For multi-hulls: use the chart as instructed, then select the model one size larger
Please note: Our sizing guide is now available in three units of measurement for your convenience: Metric Tonnes, Short Tons (used primarily in North America) and Pounds.
Select sizing guide:
Chain: As a minimum, we recommend using medium tensile / G40 / High Test chain with your Rocna anchor. (If it is available, practical and affordable, high tensile / G70 chain is preferable as it is a lighter weight to carry). For more information, refer to the knowledge base article on chain (http://www.rocna.com/kb/Chain)
Rocna's sizing philosophy: Unlike other manufacturers, our sizing recommendations are intended to provide an anchor adequate for use in most all conditions. For more on our philosophy and rationale, please consult our knowledge base article on Rocna sizing recommendations (http://www.rocna.com/kb/Rocna_sizing_recommendations)
Sizing larger anchors: For Rocna anchors 150kg and larger, the sizing calculation becomes somewhat more complicated and it is suggested that anchor selection be based on RINA Rules, Part B, Chapter 10, Section 4, as appropriate for SHHP (Super High Holding Power) anchors. After calculating a vessel's EN (Equipment Number) per the RINA Rules, the appropriate anchor can be selected as follows:
- Rocna 150 (150kg, 330lbs) - Appropriate for EN 90 - 110
- Rocna 150 (150kg, 330lbs) - Appropriate for EN 90 - 111
- Rocna 150 (150kg, 330lbs) - Appropriate for EN 90 - 112
We strongly encourage that you seek further assistance from a professional familiar with ground tackle selection for larger vessels and the application of the RINA rules. The Rocna Knowledge Base on our web site (www.rocna.com/kb/) provides you with additional information, and if we can assist further please contact us at enquiries@rocna.com.
