Anchor Issues

The Rocna anchor is a disappointment – it came loose several times in the storm in Skiathos in conditions we would never have expected to have a problem.  After significant research across the Facebook forums and the internet, the conclusion is that buying the Rocna was a mistake (at least for us)!  There are many yachts owners out there who swear by Rocna – so publishing our issues, certainly caused a heated discussion.

What WE found on Liberation was that the Rocna sets very well in mud and sand but does not set in weed.  Of course, weed is the worst substrate you can possibly have – and there aren’t many anchors which will set – but are used to the Jambo anchor and the prongs on this go through weed and hold firm!  The Jambo also holds in mud – but doesn’t hold well in sand, which is why we changed it this year.

However, the biggest issue is that it also does not RESET in the case of a wind turn, even in sand and mud.  In the Med, we experience frequent wind turns – it’s part of the prevailing wind situations – unless you’re sitting in the middle of a meltemi, where it blows constantly 30 knots plus N-NW for days on end, the wind can come S-SW during the day, turn N-NW-W in the afternoon and then anything at night (except for E which is vary rare!).  One thing is sure, it will turn.

The reason the Rocna does not reset is due to the roll bar and the concave design.  Whilst the roll-bar is intended for exactly the opposite – ie. to make sure the anchor rolls and always points downwards again – it creates a “cavity” which fills up with mud.  I don’t think I ever recovered the Rocna, without it being fully loaded with a huge clod of mud!  Apart from adding several kgs of weight for the windlass to recover, this also means that it can’t dig in again and reset.

To set it you need to keep boat speed at less than 1 knot – which is pretty impossible in a storm.  So, when it came loose it had to be fully recovered and cleaned – then dropped again with a slow reverse speed to set.  Try doing that in a huge storm!

We have identified there are a few issues:

  • The Rocna has some design issues, as above
  • The previous Jambo was great in weed but has trouble in sand – so seems like we need BOTH on board, which of course is impossible
  • Our engine is 40HP – which is perhaps not powerful enough to properly pull the anchor in
  • Our chain is only 8mm – the biggest we can get on our boat.  The chain is perhaps not heavy enough so the catenary is not ideal – the chain lifts too easily off the ground and does not help to take the pressure off the anchor
  • We yaw massively at anchor due to the design of the boat – this is adding sideways stress on the anchor

After the research, we have decided to change anchor again for a Mantus – which has the mud and sand benefits of the Rocna – it is in fact a modified Rocna which has the ability to hold in weed, and also to reset on turn.  We will also be adding a riding sail which suspends between the backstays on anchor to minimise the yaw.

We arranged for the new Mantus to be shipped to Thessaloniki Marina – along with a new riding sail – and the Rocna will be going up for sale.  I’m sure it is a great anchor for a lot of boats but it just doesn’t suit us.

You can see our anchor test on the Rocna on YouTube – which we did in very calm conditions by turning the boat on the engine and pulling in the other direction to simulate a wind turn.

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