Re: How to find fish
Your first step is to figure out where the thermocline is for the particular species you are after. Where they hang out for a particular time of the year.
This time of year the Lake Trout are pretty much near the surface as they are chasing the smelt around the tributaries like in our lakes in the Northeast.
I use a Fish Hawk Model 520 that I bought off Ebay. Paid about $75 used. This is what it looks like:
http://www.reedssports.com/Product/product.taf?_function=detail&_ID=5189
You could hang a thermometer off a string too!
During the Summer Lake Trout can be down around 150 feet deep in the lake I fish.
It looks like a big fishing reel with line and a thermometer hanging off the end of the line. You lower it down and the temperature gauge reads the temperature at that depth.
No point in going for Lakers if they hang out at a temperature between 45-55 degrees and your lure or bait isn't at that depth. Salmon hang at 50-75 degrees.
The thermocline will be much the same around the whole lake so you only have to check the temp every now and then during the day.
So now you know where they hang. Next cruise very slowly around the lake until you locate them on your fish finder at that depth and you can be sure it's probably a lake trout or Salmon.
Or cruise near other boats, or if it's a big lake cruise near some of the charter boats. The locals and the charters know where the fish are. My Navionics hot maps in my GPS shows where the fish and species are in any new lake I go on. Big time saver rather than cruising around looking for them.
Next set your downrigger weight or lead line weight to troll your bait at that depth.
Now for Lake trout troll around 1 mph, a little faster maybe 2 mph for salmon.
Lastly, you need to try worms or different color spoons, lures etc depending on the color of the water and how bright it is on that day. or as they say match the hatch. Use lures that look like what the fish are chasing.
The local bait shop will tell you what the fish are biting on.
Just a brief primer on how I do it. And you might buy this book it's only $9.99
http://www.cabelas.com/prod-1/0019648016143a.shtml
Also Google a search for "downrigger techniques" there is a lot of free advice for you on the web.
Most of all, just have fun out there and don't get frustrated when you don't catch anything but you see a lot of fish on your fish finder.
When all else fails, near the end of the day go toss a few lures or purple plastic worms at the bass near the weeds and shoreline, so at least you can say you hooked a few fish. Down rigging is a learned art and it takes practice to consistently catch fish
I caught this nice sized lake trout the first time I tried it within 15 minutes on Lake George in NY 2 years ago following all of the above tips I posted above.
The bait shop sold me 4 or 5 different lures and colors. I caught it on an orange Mooselook lure.
30 years ago I fished with a friend for hours and days on end from his boat with two down riggers and never as much smelled a fish.
When I asked the guy in the bait store what they are biting on he said same thing they bit on 30 years ago
I guess some things never change
My Daughter fishes for regular Trout by trolling a small piece of worm a few feet below the surface with an Xmas tree (a long set of metal flashers) a few feet in front of the worm to attract the trout while in her canoe powered by a Minn Kota with 30 lbs thrust.
This other method can be used at all times of the season and she catches lots of fish!