Frequently Asked Questions (FAQs)
- Does the Rocna have a Warranty?
- What do Rocna anchors cost?
- How to Choose the Correct Size Rocna For Your Vessel?
- How does the Rocna's performance compare to other types of anchors?
- Will the Rocna fit on my bow?
- Why should I consider replacing my current anchor?
- What is Roll Stability?
- What is the purpose of the Roll Bar on the Rocna?
- How does the Rocna penetrate the bottom?
- How does the Rocna fit onto the bow roller?
- What kind of boats have tried out the Rocna?
- Will the Rocna self-launch?
- How does the Rocna shackle to the rode?
- Does the Rocna support tandem anchoring?
- Can the Rocna be used with a retrieval buoy?
Does the Rocna have a Warranty?
Yes, all Rocna anchors carry a lifetime warranty against manufacturer's defects.
What do Rocna anchors cost?
The elegant design of the Rocna, combined with a Canadian based manufacturing capability, allows us to offer it to you at a price which is extremely competitive when compared to other New-Generation anchors. We believe that cruisers, particularly with larger size vessels, will be pleasantly surprised. For details, please Contact Us or your Local Dealer
How to Choose the Correct Size Rocna For Your Vessel?
Selecting the correctly sized anchor to match your boat is not quite as simple as it may first seem. There are many factors to consider, including displacement, overall length, windage profile, and the conditions in which you intend to use your Rocna. Most manufacturers provide a very simple guide using only LOA, or displacement, for their different anchor sizes. We have gone a step further.
The following chart will give you a good indication of which Rocna we would recommend for your vessel. Match your vessel’s length with the most appropriate displacement in metric tonnes (T) (2,200 lbs) - if in doubt, always tend toward the larger anchor model.
Please feel free to Contact Us if you would like to discuss the particulars of your vessel and receive a custom size recommendation.
Rocna Sizing Recommendations
Boat Length (up to) |
Rocna
Model |
|||||||||||
4 |
6 |
10 |
15 |
20 |
25 |
33 |
40 |
55 |
70 |
110 |
||
| 13' (4m) | <2T | |||||||||||
| 16' (5m) | <1T | <5T | ||||||||||
| 20' (6m) | <0.5 | <4T | ||||||||||
| 23' (7m) | <2T | <7T | ||||||||||
| 26' (8m) | <1T | <6T | <10T | |||||||||
| 30' (9m) | <5T | <9T | <16T | |||||||||
| 33' (10m) | <4T | <8T | <14T | <25T | ||||||||
| 36' (11m) | <3T | <7T | <12T | <20T | <30T | |||||||
| 39' (12m) | <6T | <10T | <15T | <25T | ||||||||
| 46' (14m) | <7T | <12T | <20T | <40T | ||||||||
| 52' (16m) | <9T | <15T | <33T | <60T | ||||||||
| 59' (18m) | <12T | <25T | <50T | <90T | ||||||||
| 66' (20m) | <10T | <18T | <40T | <80T | ||||||||
| 72' (22m) | <12T | <30T | <70T | <150T | ||||||||
| 79' (24m) | <25T | <60T | <130T | |||||||||
| 85' (26m) | <22T | <50T | <115T | |||||||||
| 92' (28m) | <45T | <100T | ||||||||||
| 98' (30m) | <40T | <90T | ||||||||||
| 115' (35m) | <80T | |||||||||||
| 131' (40m) | <70T | |||||||||||
| 148' (45m) | <60T | |||||||||||
| Anchor Weight | 4kg (9lbs) | 6kg (13lbs) | 10kg (22lbs) | 15 kg (33lbs) | 20kg (44lbs) | 25kg (55lbs) | 33kg (73lbs) | 40kg (88lbs) | 55kg (121lbs) | 70kg (154lbs) | 110kg (243lbs) | |
| Blade Surface Area (cm sq) | 460 | 590 | 795 | 1030 | 1140 | 1415 | 1695 | 1945 | 2300 | 2690 | 3300 | |
An important note on our sizing recommendations
There is a tendency amongst anchor manufacturers to recommend sizes smaller than required. For example, a certain world-renowned name-brand advises the use of a 20Kg anchor on a heavy cruising yacht of LOA up to 14.8m. This recommendation is clearly far too light. Another brand states that “a working anchor should hold up to 30 knots of wind”. Again, we consider this recommendation would lead to an undersized anchor.
We have resisted this temptation, and the above recommendations are appropriate for heavy-duty use. In our view a working anchor should hold its boat in all but the most extreme weather.
How does the Rocna's performance compare to other types of anchors?
Rocna New Zealand have performed extensive testing on the Rocna as well as other anchor designs. Their results show the Rocna is a top performer, both in its ability to set quickly and to provide powerful holding. Read the fascinating results on their demonstrations & testing page.
Will the Rocna fit on my bow?
Experience has shown that most boats which can use a plow or claw type anchor have no problems accommodating a Rocna. If you would like to double check, just Contact Us and we would be happy to send you a dimensioned drawing of your choice of anchor so that you can check the clearances for your boat.
Why should I consider replacing my current anchor?
If you're happy with your current anchor, you probably shouldn't. If you're like most cruisers, however, you have from time to time experienced difficulty in getting your anchor to set or, even worse, having had your anchor drag when the winds pick up or change direction. Few things are more alarming.
The Rocna was designed from the ground up to address the key limitations shared by most older and many newer anchor designs. Many of these designs suffer from some or all of:
- limited holding due to relatively small blade area
- poor penetration in difficult bottom types
- a tendency to roll-out under heavy or veering loads
- a tendency to move about on the bow roller
- insufficient strength in the shank or in key load-bearing members
The Rocna addresses each of these points. Its large blade area, relative to its weight, ensures tenacious holding even in softer bottoms. The combination of a chisel tip, roll bar and skid plates ensure fast penetration and rapid burial even in difficult bottom types - typically within 3 feet. The optimized geometry provides roll stability under heavy and veering loads. The Rocna's curvature of the shank above the blade provides a positive lock on most bow rollers, preventing vertical motion while underway. And finally, the strategic use of a modern, high tensile steel provides incredible strength out of proportion to its weight.
What is Roll Stability?
Once the Rocna anchor is set, it remains buried even under extreme loads. Many other anchor designs will "roll out" when overloaded, but the Rocna stays embedded and maintains its attitude. In the event that the Rocna is forced out of the bottom, for example by hitting a rock, it will immediately adopt its rapid set attitude and begin to re-bury.
Veering loads can also cause many other anchor designs to "roll out". The Rocna remains buried under most changes of load direction, and even with a 180 degree shift in pull will reset immediately.
What is the purpose of the Roll Bar on the Rocna?
The Roll Bar replaces the lead-weighted tip used in many other anchor designs, in that it ensures the anchor will adopt the correct setting attitude - on its side with the complete anchor weight supported between the skid plate, the shank end, and the blade chisel-tip. The advantage of the Roll Bar over a weighted tip is that, for the same weight of anchor:
- it allows a much larger total blade area, providing greater holding power
- it allows the use of heavier materials in the toe and shank - strength where it is needed.
How does the Rocna penetrate the bottom?
Once placed into the correct setting attitude by the Roll Bar, the forward movement created by tension on the rode creates a turning moment, helping to force the chisel-tip into the bottom. As resistance builds the dynamics alter, forcing the anchor to roll upright and placing even more downwards pressure at the chisel-tip.
As the Rocna penetrates, the final angle of attack will be somewhat determined by the bottom type. Typically the bottom will get denser as the anchor penetrates deeper, and this change in density forces the tip further down, resulting in a blade angle of attack nearly at right angles to the direction of pull. This attitude provides strong resistance without deep penetration.
In soft bottoms, the Rocna continues to penetrate deeper, with the large blade area providing strong resistance.
 |
 |
|
| This 20kg Rocna Anchor set in less than 3 feet! | ||
How does the Rocna fit onto the bow roller?
The shank of the Rocna is shaped to "lock home" on most bow rollers, with very little room to move up and down. This is particularly important when sailing or motoring into waves, as the combination of pitching moments and wave impact can place enormous force on a bow-mounted anchor. Not all anchors "lock home" as securely as the Rocna, and damage can result.
What kind of boats have tried out the Rocna?
To date most feedback on the Rocna Anchor has come from New Zealand, where it has been available for some time. Customer Testimonials from both sail and power boat users can be viewed under "Customer Stories" at the designers website (Click here)
Will the Rocna self-launch?
The weight distribution of the Rocna is such that it will self-launch on most boats.
How does the Rocna shackle to the rode?
The Rocna has a slot in the shank large enough to allow the head of the shackle to pass through, eliminating the need for two shackles and allowing the maximum shackle size supported by the chain to be used.
Does the Rocna support tandem anchoring?
Yes, the Rocna has a hole in the shank to allow two anchors to be connected in "series". This technique, called tandem anchoring, is used under extreme conditions and can significantly increase the holding power over a single anchor, or even over two anchors on separate rodes. Earl Hines describes this technique, among others, in his excellent book "The Complete Book of Anchoring and Mooring".
Can the Rocna be used with a retrieval buoy?
Yes, the Rocna has a hole in the blade for attachment of a buoyed retrieval line, in case of anchoring in foul ground, or in tight quarters where it's helpful to mark the anchor position.