Without a fish finder Round Valley will be tough if you are looking for trout. This time of the year you may need a downrigger, or lead core line to get down to them. Flat line trolling will bring your bait down 15 feet or so at most depending on your lure, how much line you have out and your speed. In August that probably isn't nearly deep enough for any trout. The browns and rainbows will be below the thermocline. A fish finder will tell you where the trout are holding and I suspect it will be below where you can get trolling with a flat line in a kayak. Before I got a downrigger and lead core trolling line, I trolled a 2 oz weight on a three way swivel to get my lure down below it's normal track. But you still need to know where the fish are holding, otherwise it's a guessing game.
Lakers will be down really deep, 70+ feet down. If you can find a map of the lake with contour lines it may help you find the proper depths. There is a very good map of Round Valley available in many NJ fishing shops that will help you determine the depth where you are fishing. This website has some decent info too.
http://roundvalleyfishing.com/map/ h
In a kayak, jigging is probably the only realistic way to reach lakers, but you're going to need a pretty calm day to keep your jig near the bottom in 70+ feet of water. If it is really calm day you might be able to get a 3/4 oz Binsky to the bottom, but a 1 oz or 2 oz marabou jig is probably a better bet. That or drifting a herring (herring works better than shiners) on a three way swivel with a 1 - 2 oz weight to bring it to the bottom.
Round Valley is tough for all but the veteran RV anglers and a lot tougher without a fish finder.
Hope all this helps. Thought it hasn't helped me much over the years.
As far as trout at Spruce Run, forget about it. I've heard of some people catching trout there, but it is not a trout fishery. Try Merrill Creek Reservoir instead if you want to target trout. Most of the above will apply there as well.
