Mystery of the tide

Apparently, Perth is one of the few places on this planet that has a diurnal tide where there is only one high and low tide per day. Having said that, on a certain lunar phase, we still get a sort of double tides (mixed tides) where there are two highs and lows at different heights.

Anyway, as we all know the tide is something people need to understand if they are interested in catching fish in saltwater. This can be a daunting task for someone who has only been fishing on freshwater as it was for me for sometime.

However, once I got some understanding of how the tide works, reading the tidal movement has become very interesting for me. It is like a predicting a hatch of insects. In stead, on saltwater, it is about guessing how bait fish moves as the tide goes up and down.

西オーストラリアのパースでは、通常潮の満ち引きが日に一度。同じ様な潮の動きがある場所が世界で数カ所あるそうです。

海での釣りで、釣果に一番大きく影響するのが潮の動きです。鱒釣りの場合、魚のいる場所は、洪水や渇水などの極端な要因がなければ、シーズンを通してだいたい似た様ですが、海の場合、３０分もすれば、それまで良かった場所にまったく魚がいなくなりますし、その逆もあります。

鱒釣りしかしていなかった時は、たまに暇つぶしに海に行ってもアタリすらなくて、海の釣りは、運任せの釣りだと思っていましたが、だんだん潮の流れとそれによる魚の動きが分かってくると、ただ海に行って、キャスティングを続ければ魚が釣れるという、簡単な話では無い事が分かってきました。




Mike is trying to land his big catch on Swan River

I think our two rivers, Swan and Canning have each distinct characteristic in terms of the tidal movement. Swan is longer and somewhat narrower. Although it meanders around, the bank is much more straight, so the tide moves bit more freely which makes bit easier to guess how the water is moving on a particular tidal stage.

Compared to Swan, Canning is shorter (the tide only pushes as far as the Kent Street Weir) and quite broad for its length. There is a number of points and narrow necks which interfere how the water moves, and it seems that the wind plays a big roll on how the water moves on the Canning as well.

Because of these, I find reading the tidal movement is very challenging on Canning sometime. We often go down to the river thinking the water should be moving from left to right, yet when we get there the water can be moving in an opposite direction instead.

If I get to a chance, I really love to talk to someone expert in hydro-dynamics or something, so that I can get a better understanding of how the tidal water moves depending on a given topography.

パースの町には、Swan Riverと、その支流のCanning Riverがありますが、Swan Riverの方は、いわゆる普通の川で、蛇行はするものの、岸は比較的真っ直ぐで、潮の流れもスムーズです。

これに比べて、Canning Riverは、岸と岸が極端に狭まった場所やとんがったポイント、それからフラットやドロップオフやベイなど、潮の動きに影響する物が色々とあって、水の流れがどう動くのかをタイドチャートから予測するのは難しいです。

いずれにせよ、河口や海の釣りの面白さは、潮の動きを読む事にあると思います。

Watching how the tide was moving on Swan on Saturday evening