How To Find Depth Of Water When Fishing

How To Find Depth Of Water When Fishing: 4 Techniques

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Something that you might know about fishing, especially when it comes to finding fish to catch, is that the depth of the water does matter. You need to know the depth of the water to figure out where the fish are, and you need to know the depth of the water so you know what kind and the weight of the lures to use. How to find the depth of water when fishing is what we are here to find out today.

Well, to be fair, there are a number of ways to find out how deep the water is where you are or where you plan to go fishing. You can use various methods and tools including a good old depth finder or fish finder, a marked rope or fishing line, a weight, and a float, and a few others too.

How To Tell How Deep You Are Fishing

Let’s find out the easiest ways to determine water depth for fishing right now.

1. Use A Depth Finder

The first and easiest way to figure out the depth of the water where you are fishing is to just use a depth finder. Depth finders are cheap to buy and there are lots of them out there.

They are simple tools, some handheld and some that attach to your boat, which use sonar to figure out the exact depth of the water.

To be fair, you should just get a fish finder, because these use sonar to find fish, plus they also map the lake or ocean bed, they show you obstacles and contours, and yes, they provide you with depth measurements too.

This is by far the easiest way to go about the whole thing. Fish finders are super convenient, easy to use, very informative, and a half decent one is not going to cost you all that much money either.

2. Use A Marked Rope Or Fishing Line

Another easy way to determine how deep the water is where you are, is to use a marked rope or fishing line. Now, keep in mind that if you are using a rope, there is only so much rope you can take with you in a fishing boat, so this is a bit limited.

If using a rope, you want to tie something weighty to the end of it, like a rock, brick, or anything else heavy enough to sink to the bottom.

A rope is a good way to go if you know that the maximum depth is not over 100 or 125 feet, and you need to figure out what the exact depth is. Simply mark the rope at regular intervals which you have measured out.

This way you can get a precise reading on the exact depth of the water. Fishing line is a bit more versatile here, because you can have a much longer length of fishing line when compared to a much thicker rope.

You can also tie a weight to a fishing line and let it sink, and have it market with regular intervals. However, if you are an angler, you know that fishing line gets all tangled up, so pulling a whole lot of it out of the water, covered in markings, may get a bit confusing.

We would recommend the rope option for this.

3. Use A Weight & Float

Another good way to measure the depth of the water where you are, for fishing purposes, is to use a weight and a float.

Simply hook or tie the float onto the fishing line, attach a weight where you would normally put the hook, and let it all sink down. If you have a bobber, you can just measure the distance between the bobber and the weight to get an accurate depth reading.

If you have attached the line to the float, you will need to keep readjusting it. For instance, if you have not left enough room between the float and the weight, the weight will pull the float underwater.

So, if the float goes under, increase the distance between the float and the weight, until you get to the point where the weight no longer pulls the float under, which means that it has reached the bottom.

4. Use Maps & Online Information

One of the best things to do to find out the depth of the water where you want to fish is to just check online. Most rivers and lakes that are popular for fishing will have online data about it, pretty specific too.

There you can find out how deep the water is at a certain distance from the shore. You can then just go to the lake or river, measure the distance from the shore, and then you will know exactly how deep the water is.


As you can see, finding out how deep the water is wherever you are is really not all that hard. However, do keep in mind that if the water is excessively deep, besides using a depth or fish finder, you might have problems.

Some really deep lakes, and yes, oceans, can be hundreds and hundreds of feet, or even hundreds of yards deep, in which case the resources for determining depth may be a bit limited.

Yet, if you are in a normal lake or river, one that is not excessively deep, you should be able to use and of the above methods to determine the depth for optimal fishing results.