14 June 2008, at Sea.

The tide at Seymour Narrows was slack this time around 01.30 in the morning and that meant I did not have to rush nor go too slow to get there. I like it when Mother Nature conforms to the company schedule. It makes life a lot easier. Thus we aimed for going through around 1 am, when there was still a little bit of flood left but less than 4 knots and that is safe to navigate. While approaching the Narrows we had to speed up a little bit as we had to overtake a slow barge and tow and on the other side the Serenade of the Seas was approaching. If we waited for him that would have meant a delay of 45 minutes, but by going through a little bit earlier we could be first.

I have now been writing blog after blog about the importance and impact of Seymour Narrows on our time schedule. Here is a little explanation of how it works.

http://www.dairiki.org/tides/daily.php/sey/2008-06-13

See above a diagram from today. I use myself the tables issued by the Canadian Pilot Association but the above is accurate enough to safely work with. The current at Seymour Narrows changes direction four times a day and each day it shifts a little bit as the tides are under influence of the sun and moon. Strong winds can have a little bit of influence as well but not that much. Where the color goes from yellow to green in the diagram is the moment of slack tide. When it goes from flooding (yellow) to ebbing (green). Flood is in the Narrows in the direction south, Ebb in the direction north. So this time we had to push against the flood while going through and later had the ebb current with us. A ship such as the Veendam can safely transverse the Narrows with currents of four knots or less. It can be done with more, but it means that you have to give sharp rudder orders and that makes the ship list, it drifts much more from the intended track and might come too close for any other ships that might happen to be in the area. The more current, the less control you have over the vessel.

From Vancouver it is 96 miles to the Narrows that means at least 5 hours at full speed plus slow down time. So the earliest that you can make a tide in the evening would be around 11 pm. This mornings slack (see line at the bottom of the diagram was at 1.25 am) Thus I went for that tide. Now look at the yellow bit. The diagram goes under the 4 knots between 00.30 and 00.45 am. Thus I aimed for 1 am. If you go for full slack the barges and log tows might be in the way, as they either like slack tide or the end of the following tide as they go so slow and have difficulty controlling their tows.

If I would be late for one reason or the other, the latest I could go through (see the green bit) would be around 02.30 am. If I would not make that, the next chance would be around 7 am. that would delay the cruise by about 7 hours compared what it could have been. It does not take much imagination to see what a seven hour delay could have for an impact on a cruise. It is almost a full port day. Thus the times of the slack tide are of paramount importance to an Alaska Cruise ship captain and the whole cruise schedule at the beginning and the end of a cruise is built around it.

I went through once with 10 knots of current but that is a story I will tell sometime in the future.

This time we went through at 00.45 hrs. and that meant four knots. We measured only 3 knots, but then the tides do not always follow the prediction or the diagram. Once through we met the Serenade of the Seas who was in a hurry southbound as she had a very tight schedule to make. I took the scenic route so at 07.30 we passed by Alert Bay for the totem pole viewing. With some whales showing in the afternoon and evening it was a good day.

Tomorrow we are in Ketchikan, where they seemed to have located the rains clouds again.