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May 2003 Volume XV Issue 1 Abridged Edition |
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Tidal AreasBy Phil Sego phil@philsego.com Tidal areas – such as salt marshes – are incredibly beautiful areas, abundant with wildlife, and particularly teeming with migratory birds. These places are usually quiet and unspoiled. Exploring tidal areas is easy if you pay attention to the tides. If you neglect the tides, you can easily become lost, surrounded by a sea of mud and muck, stranded until the tide comes back in. The other attraction of a tidal trip is that with a little planning, you can have the current carry you one way – and then take you back! This can easily be done, but requires gaining a little knowledge of how tides work. Planning a tidal trip requires a few extra items:
Tide schedule: Tide intervals are simple. If it’s high tide at 6:00am, low tide is 6¼ hours later – at 12:15pm, and the next high tide is at 6:30pm – give or take a few minutes. A tide chart will tell you exactly when the tide is expected. You also know that the moon causes tides. It follows that the presence of certain moon phases equals the presence of tides at a specific time. A full moon or new moon means that high tide will be at about noon. First or last quarter moon means that low tide will be at noon. Of course, this applies to coastal tides. Inland tides, like those at Great Bay, deviate from this, depending on their distance from the open ocean. (see below). If you have trouble finding the tide schedule for a specific spot, don’t hesitate to call a harbormaster or nearby marina. They will most likely have schedules adjusted for your put-in and destination. Bring a good map: One of the most amazing things about tides is how different everything looks at high tide vs. low tide. Tides in Hampton are 9 feet (from low to high). That’s enough to swamp islands, move shorelines, and change the appearance of an entire bay. When you first put in, note a few TALL landmarks on the map. Take compass readings to establish your location. Topographical maps are better than road maps at helping you figure out your location. We’ve all learned that magnetic north isn’t true north. While most good maps will include a note about compensating for the deviation between these, road maps and street atlases don’t. But here’s a simple thing to keep in mind: For coastal NH, your compass points 16 degrees to the WEST of true north. The wind: Wind is the trickiest part of tidal paddling. Winds can completely negate the tides and make a return trip impossible. For example, on one trip, we started 2 hours before a noon high tide and paddled west on the Parker/Mill River, hoping to return 2 hours after high tide. But strong onshore breezes at 20 mph just about stopped the tide from going out. The meager current was offset by a 20 mph headwind. AND – just to top off this painful learning experience – at high tide you’re not sheltered by any land or trees whatsoever. (If you’re wondering, we were unable to paddle and had to line the boat through the salt marsh back to the put-in.) That’s where the extra warm clothing can come in handy. In my example, we were able to line the boat back. But on Great Bay, you could easily become stranded on the mudflats. An extra jacket, extra water, and a few energy bars can make the difference between a serious mistake and just a boring wait for the next tide. Tidal rivers and Bays: As a rule of thumb, tidal water flows at around 2 miles per hour on a typical tidal river and on Great Bay. This means that if you’re 2 miles up a tidal river, high tide will be one hour later than at the mouth of the river. This is important to note if you’re planning a tidal river trip. If high tide is at noon, leave at 10am. Stop at 12:30 for lunch. The tide will continue to rise until 1pm – because you’re upriver! The tide won’t “turn” until about 1:30; it will be very slow until about 2pm. Tidal flow isn’t linear – it doesn’t flow at 2 mph, stop dead one second, and then travel at 2 mph in the other direction. It’s fastest at roughly the midpoint between high and low tides, and slows as it approaches the high or low point. Of course, this is an oversimplification of exactly how tides flow, determining the real flow is part of a complex mathematical formula. Appropriate boats: On the tidal trips that I’ve led, we’ve had a mix of tandem canoes, touring kayaks, and sea kayaks, all of which seem to do very well. Solo canoes are not appropriate, as there are always windy stretches with no shelter. All these facts and figures are generalizations based on trial-and-error, some research, and some of the participants of the rec.boats.paddle discussion group. No matter how much you study tides, you could still get caught on mudflats. Be prepared! Ideal tidal trips:
Websites with more information:
The Parker and Mill Rivers wetland area is a perfect place for tidal paddling. This river flows roughly east-west – so be careful of strong onshore winds that develop on sunny days. |
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