For many years the only available "depth charts" of Maine lakes were those that were created through a federal program in the 1930's and 1940’s. The intent of this data collection was to aid in the development of a fisheries management plan for a given water body and to determine the ability of a water body to sustain a fishery.
The depth data collection methods used then seem crude by today’s standards. Think back for a minute, before the time of the personal PC, compact sonar devices (fish finders or depth recorders) and way before we could even imagine a GPS (Global Positioning System). From what I have been told, depth data was collected by teams of two men, in both the summer and winter months. Finding the depth was not as difficult as determining the exact location of any given point. A lead line (a weight tied to a string that was marked off in one foot increments) was simply lowered to the bottom to record the depth to the nearest foot. This method (while extremely accurate) was very time consuming, particularly when you had to cut a hole through 4 feet or more of ice.
Determining the precise location of a point was the most difficult part of this operation. Geographic landmarks such as islands, points of lands, and other natural (and sometimes man-made) reference points were used when they were available. Occasionally, in the absence of geographic landmarks, two sticks were positioned with one at the waters edge and the other placed 20-30 feet behind. While the crew moved further and further away from shore these sticks were kept in line to assure they were working in a straight line. Coupled with a compass, tape measure, and lead line, this was about as accurate as they could get. Of course this data was susceptible to errors and it sure seems primitive now, but in the 30's and 40's that was cutting edge technology! Utilizing these methods, depth maps were created for almost every waterbody in Maine. Today, people refer to these maps as “the old IF&W depth maps” since they were utilized and kept on file by staff at the Maine Department of Inland Fisheries and Wildlife.
Since then, some lakes have been re-surveyed by college students studying different aspects of our fantastic waterways. But our lakes have never been re-surveyed with the intent of the final product being a map made available to the general public. Maine Lake Charts intends to change that. For the first time ever, digitally enhanced, geographically correct depth data is being collected for a variety of our lakes and ponds. Maine is lucky to have around 2700 lakes and ponds over 10 acres in size. As much as we would like to be able to snap our fingers and have all new depth data for all of our lakes it just isn’t possible. Therefore we are keying in on the more popular lakes first. We plan to continue collecting data in the months and years ahead and even we don’t know where this will end.
The bottom contour of our wonderful Maine lakes can change in an instant. Maine lakes are full of ledges, rock-piles and other underwater hazards. We can thank the glaciers for that. All of our charts display some type of depth information since they are next to worthless unless they do. If you have looked at the charts we sell online, you will notice that next to some of them is the phrase “Features all new depth information.” These are the lakes for which we have collected and processed new depth data, utilizing the technology of today. If this phrase is not present, the depth data displayed on our charts comes from the “old IF&W depth maps” since this is the only readily available depth information. We understand (and hope you will too) that this data is susceptible to errors. As any experienced navigator knows, caution should always be used when operating in unfamiliar waters, whether he is using a chart or not.
Please note that all of our charts, whether they contain depth data collected by us or data from the old IF&W maps are not intended to be used solely for navigation. Only a few of our Maine lakes are marked with navigational buoys and ultimately it is the operator of a watercraft who is responsible for the safe operation of his or her vessel. This information is provided only to give the user a general idea of what they may expect to see for depth on a lake.
The depth data collection methods used then seem crude by today’s standards. Think back for a minute, before the time of the personal PC, compact sonar devices (fish finders or depth recorders) and way before we could even imagine a GPS (Global Positioning System). From what I have been told, depth data was collected by teams of two men, in both the summer and winter months. Finding the depth was not as difficult as determining the exact location of any given point. A lead line (a weight tied to a string that was marked off in one foot increments) was simply lowered to the bottom to record the depth to the nearest foot. This method (while extremely accurate) was very time consuming, particularly when you had to cut a hole through 4 feet or more of ice.
Determining the precise location of a point was the most difficult part of this operation. Geographic landmarks such as islands, points of lands, and other natural (and sometimes man-made) reference points were used when they were available. Occasionally, in the absence of geographic landmarks, two sticks were positioned with one at the waters edge and the other placed 20-30 feet behind. While the crew moved further and further away from shore these sticks were kept in line to assure they were working in a straight line. Coupled with a compass, tape measure, and lead line, this was about as accurate as they could get. Of course this data was susceptible to errors and it sure seems primitive now, but in the 30's and 40's that was cutting edge technology! Utilizing these methods, depth maps were created for almost every waterbody in Maine. Today, people refer to these maps as “the old IF&W depth maps” since they were utilized and kept on file by staff at the Maine Department of Inland Fisheries and Wildlife.
Since then, some lakes have been re-surveyed by college students studying different aspects of our fantastic waterways. But our lakes have never been re-surveyed with the intent of the final product being a map made available to the general public. Maine Lake Charts intends to change that. For the first time ever, digitally enhanced, geographically correct depth data is being collected for a variety of our lakes and ponds. Maine is lucky to have around 2700 lakes and ponds over 10 acres in size. As much as we would like to be able to snap our fingers and have all new depth data for all of our lakes it just isn’t possible. Therefore we are keying in on the more popular lakes first. We plan to continue collecting data in the months and years ahead and even we don’t know where this will end.
The bottom contour of our wonderful Maine lakes can change in an instant. Maine lakes are full of ledges, rock-piles and other underwater hazards. We can thank the glaciers for that. All of our charts display some type of depth information since they are next to worthless unless they do. If you have looked at the charts we sell online, you will notice that next to some of them is the phrase “Features all new depth information.” These are the lakes for which we have collected and processed new depth data, utilizing the technology of today. If this phrase is not present, the depth data displayed on our charts comes from the “old IF&W depth maps” since this is the only readily available depth information. We understand (and hope you will too) that this data is susceptible to errors. As any experienced navigator knows, caution should always be used when operating in unfamiliar waters, whether he is using a chart or not.
Please note that all of our charts, whether they contain depth data collected by us or data from the old IF&W maps are not intended to be used solely for navigation. Only a few of our Maine lakes are marked with navigational buoys and ultimately it is the operator of a watercraft who is responsible for the safe operation of his or her vessel. This information is provided only to give the user a general idea of what they may expect to see for depth on a lake.
If you have any additional information regarding the old IF&W depth maps or any other questions, please contact us at: sales@Mainelakecharts.com.
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