Pine Harbour Silting

[unpc 5]

It looks to me as if the week of gales has caused quite severe silting in the Pine Harbour channel in places. From the tide times and depths I calculate that there are at least two areas where the depth is about chart datum or less. These are from around the first and second green poles outside the entrance even out 3 metres or so. I dare say one can get through in the middle on the wrong side or coming out, but it doesn't help coming in particularly if passing the catamaran ferries. On rough guesses if the channel is 16 m wide the ferry allows 3 and is 6 m I allow 3 and am 3 m that leaves 1m between us. Too close in my view.

On my calculations currently, at 1.2-1.4m draft there would be problems using it 2 hours either side of low tide. The loss of another .8 m on spring tides adds about another hour to be safe with wind effects etc. Launches would have less of a problem but would still need to make some allowance.

I contacted the marina who seemed unaware of a problem and said dredging had been done for the year.

On monday two boats grounded for some hours. It was amusing in a way to see people pass then ground 100m later. They were able to power through the mud. Also amusing to see a couple of boats shortcut the channel altogether and cut across the mudflats at low tide or just after with a low tide level of .8 m and ground though fortunately able to get off.

Incidentally I note the coast guard book gives non daylight savings tide times from the Linz site. Although there is a note to that effect it could trap the unwary.

With hindsight I doubt the advisability of getting a tow off unless the grounding is minimal, because of the narrowness of the channel, and the difficulties of close quarter manouvring with cross wind and likely being shorthanded. Similarly I doubt coastguard should be called. Easiest to wait. However if a deeper keeled boat gets stuck just outside the entrance to the marina itself in the middle of the channel that may well stop the ferries and get the problem dealt with.