Gps

luckybob99 · 31 August 2006, 08:30

I was out last weekend playing with the boat getting use to the sonar and gps etc . So I thought I know I'll have a search for a mark/wreck.
So I checked my Gps , set the correct datum and input the details.
When i arrived there was 3 diving boats in the close area so I knew I was near . But could I find it with the sonar , no i could not , so off I went with my tail between my legs.
Question I am using a Garmin 125 GPS .Is it worth paying for the DGPS to gain accuracy or a new "wass" enabled unit ( if this is on in the uk yet seems to be a subject on its own) or do I just need more pratice......

Pete7 · 31 August 2006, 09:19

The quality of the echo sounder might be the issue rather than the GPS. I prefer Lowrance because they are quite powerful and will often pick up details of a wreck that some of the other makes won't find, an that includes the cheaper Eagle and Garmin ranges. If there were 3 other dive boats in the area then your in the right place and the GPS is working but it can be diffcult to pick out a definate man made shape of a wreck from other underwater objects. A square or petal shape search of the area would normally find a wreck but its a lot quicker with several other boats.

Pete

Simon B · 31 August 2006, 11:50

Dont lose heart, it isnt easy finding wrecks. If your sounder doesnt have auto zoom or bottom lock or 2 or 4 times zoom on a 30metre reading you are looking for a small change in the height of the reading.

Also your other settings can have a great bearing on how sensitive your sounder appears. Noise or clutter reduction and transducer position again will impact it. It took us a while to get ours et up to optimum (Lowrance x107DF) DF helps alot as well, 50k transducer better for depth.

luckybob99 · 31 August 2006, 15:11

Thanks for the answers guys . Hope its not my sounder cos I have just replaced it .Its a lowrance x135 ....

jyasaki · 31 August 2006, 17:05

I've found that unless you have about 8-10' of relief, or the structure you're looking for is really big, it's nearly impossible to locate on sonar without running a lengthy pattern and paying *really* close attention to the sonar screen.

To see the object, you have to cruise directly over it at a speed which will show you the difference between the normal bottom and the top of the structure. Harder to do than it sounds.

When diving, I go by the GPS (with WAAS corrections, usually) for known sites, and use the sonar for finding new structure, or things like the edges of pinnacles and such (i.e. an anchoring aid.)

Hope this helps;

jky

luckybob99 · 31 August 2006, 18:33

so I got to ask this outright is waas working in the UK yet ??

Poly · 31 August 2006, 19:06

Quote:

Originally Posted by luckybob99

so I got to ask this outright is waas working in the UK yet ??

Yes, although it is more correctly called EGNOS in europe - been "officially live" since July 06 (although I think it was working most of the time a while before then).