Recreational side scan to find wrecks

[Flips]

We have been given a large number of fishing spots for the local area which include a number of sunken fishing boats and crashed planes from WW2. They come from a number of different sources and probably aren't very accurate, i know of some people who have tried to dive some of the numbers in years gone by without my success. With the improvements in consumer sonar I'm thinking of getting something like a Lowrance HDS 7 gen 2 or 3 with a total scan transducer and going on a hunt.

I'm after some feedback on how this equipment would go at trying to find these wrecks in 60-130ft of water. Targets would range from 30ft boats to plane wrecks (WW2 fighters and bombers). Unsure of how much of the planes would have survived, would be good if there was fuselage but may only be props and engine blocks. Search areas would probably range from 500ft sq up to 1 mile sq.

I've never done anything like this before so i'm open to any feedback

 

[Johnoly]

..... I'm thinking of getting something like a Lowrance HDS 7 gen 2 or 3 with a total scan transducer and going on a hunt.......... Targets would range from 30ft boats to plane wrecks (WW2 fighters and bombers). ....

Different msg board but there was some great discussion going on especially with transducer angle and kw power with balancing it to give you the very best view at a specific depth.

Tony is a member here on SB and a commercial diver and is very knowledgable on it and you might want to contact him.

100days-a-year

 

[Peter69_56]

I have 2 garmin sounders and use those for locating wrecks. One is set to chart (GPS Map 952) and the other set for side scan/down scan or Traditional with zoom (Echomap chirp 95/ GT52). I use the 952 on chart as its touch screen and so easy to manipulate, the 95 is better as a fixed sounder being button driven and has sidescan.

I am very happy with it to date and have located wrecks down to 55m.

 

[100days-a-year]

Thanks Johnoly!

Gonna want to get a Garmin.AFAIK they are the only ones with a lower frequency transducer available that allows wide swaths to be covered.My GT51 thru hull transducers are good to 390' out either side before the signal is to attenuated to be useful.

Humminbird used to offer a low frequency transducer that may still be found used on ebay.

Where are you located and what format are the coordinates?It may be that they are innaccurate due to being poorly converted LORAN numbers.

 

[Flips]

I'm new to this so don't have any brand loyalty. Looking at the various websites they all seam to cover similar frequencies bands when looking at the all in one transducers (Lowrance Total Scan and Garmin GT50M-TM). Is that the difference you mentioned?

In terms of the accuracy since they are from some difference sources to the same wreck i figured the differences might come from how they were captured or rounding errors, some end in 000 which is around mileish error if numbers have been dropped off

 

[MaxBottomtime]

 

[Flips]

They are some great images, hopefully we can get something like that but before then we need to find them!

 

[broncobowsher]

The downvision looks really impressive. So when will there be a highlighted arrow that shows "divers" and "bubbles"?

 

[Peter69_56]

I'm new to this so don't have any brand loyalty. Looking at the various websites they all seam to cover similar frequencies bands when looking at the all in one transducers (Lowrance Total Scan and Garmin GT50M-TM). Is that the difference you mentioned?

In terms of the accuracy since they are from some difference sources to the same wreck i figured the differences might come from how they were captured or rounding errors, some end in 000 which is around mileish error if numbers have been dropped off

One important factor many forget to attach with positions is the datum the sounder is set to. I use WGS84. The difference between positions with different datums can be hundreds of metres. My Garmin map shows map positions for wrecks shown as a circle (clearly from an existing map) unfortunately after locating the wreck I have found that the map spot is from AUS66 datum but put onto an electronic map using WGS84 so some 100 metres out east/west and 160m out north/south. And the errors are consistent on the electronic map. So I would suggest you ask the person supplying the information what datum they are using. If you get a blank stare, it probably means they have no clue as to what the GPS was set for.

 

[rhwestfall]

The Raymarine Dragonfly is an economical, and very crisp image. My only dislike is the very long boot time.

YMMV