Current position and recent track
With the NZ MetService forecast of wind gusts up to 50 knots from the SW tonight and through tomorrow I've decided to leave the marina at Lyttelton and head for Diamond Harbour.
I tied up to a mooring buoy owned by the club here which was, by various different people's reports, rated either for 4 tonnes or 20 tonnes. I am 14 tonnes. Although this place is relatively sheltered from all of the southerlies I've still recorded peaks here on the instruments of 25 knots while the other side of the harbour has been reaching 35. The wind has bent around a bit so it's coming into where I am from the NW where it's otherwise blowing a SW'erly. I can see some flatter water over the other side of the harbour but I don't know if the wind speed there is any more or less than here, and I'd be without the benefit of the mooring buoy.
I'm quite close to shore here but my estimate is that I'd need to drag about 60 metres before there was any bother. I have 2 anchor alarms set, one on my GPS and one on my phone (which seems to be a bit hit and miss as to its location).
I've dropped my anchor at what should have been about a 90 degree angle to the rope leading to the mooring buoy, however with the wind moving from SW to NW that angle is more like 30 degrees at the moment. I have put extra slack on the anchor chain (I let out nearly 12 metres) and the chain appears to be dropping straight down off the roller with the mooring buoy ropes at full stretch. In the last 18 hours I haven't shifted more than the normal amount you'd expect from swinging about (my GPS antenna is on my stern rail which means it exaggerates the swing compared to one, say, on my bow).
I've tied a fender buoy to 5 metres of rope and shackled it to the slot on the shaft of the anchor (it's a Manson Supreme). It's 30cm off high tide now and I just dinghied out to the rope and there's a bit less than a metre of slack in it right now, so the buoy shouldn't be in any danger of lifting the anchor even at high tide.
The worst is apparently scheduled to hit around 1am tomorrow (according to both MetService and PredictWind), so I guess I won't be getting a lot of sleep tonight. If we get through that without dragging either mooring or anchor then I will probably sleep like a brick for 2-3 days. I didn't get much sleep last night either, being up constantly to check position as first one then the other anchor alarm went off as we shifted into our current position from being swung the other side of the mooring.
What have I forgotten? Should I take in some anchor chain and tension it at high tide to allow the chain to take some of the load from the mooring ropes? Should I drop the mooring buoy completely, heft the anchor and head to the other side of the harbour (but then I'd be on anchor alone and this mooring appears to be holding).
Can't say I'm entirely happy but the options were to stay in the marina where some boats have been extensively damaged in these sort of winds, or to head for an unknown anchorage elsewhere, or to come here where I've already been and scouted out the mooring.
Advice from the locals was to do pretty much what I've done. The other advice was to go to Purau nearby but some of the old heads said that a boat my size was not going to have enough swing room there.