We have a 20kg Rocna on our Seawind
1000, this anchor replaced several Ploughs which did exactly that, ploughed and dragged.
We're very happy with the Rocna on an all chain rode
with a heavy rope bridle
. Factors comments on the convex vs concave design are relevant, the Rocna can bring up a fair bit of bottom "samples" for your viewing pleasure, we get underway slowly with the anchor just breaking the surface and find the water
movement sluices it pretty clean in no time, it can then be retrieved without getting mud every where. Having a foredeck pressure washer (thanks Seawind) soon disposes of any thing coming off the rode
during retrieval. This anchor really bites into the bottom and we've yet to drag including in some pretty heavy conditions. We never use the winch
only to break out, we tend to motor
slowly ahead until the rode is nearly vertical, clinch it off on the main cleat and use some engine
power or wave action to break out.
We still have the last plough on board as an auxiliary anchor and also carry a small Danforth which does double duty as the dinghy
anchor and a surprisingly effective (give n its size) kedge or stern anchor for when there is a need to prevent the boat swinging.
The size of the Rocna is possibly overkill for our size boat (33ft 5.5t) but given our previous experiences we wanted to be sure. As a result we get a good nights sleep.