Help with locate bass in extremely deep water.

[Zsolt Rebek-Nagy]

Hi Guys,

 I am  a new member.

I living in south florida, in fort lauderdale area, in city of Margate.
I have a big problem to locate the big bass in the lake when I fish, I thought maybe you guys can give me some advise ,how to find those scoundrels.
Ok, so the lake is behind my backyard and I am fishing from a little pond boat, which is perfectly fine on the lake. 
The lake is about 500 acres , and my biggest problem with the lake is that ,is zoo deep. The deepest point is 170 feet. The average deep close to shoreline in about 15-35 feet.
There is some area with vegetation, just a simple flat out or like a little " bay" area, but those are also at least 6-15 feet deep. I know that the bass is moving to the deeper water in cold conditions. What is the deepest that  bass would go? What area the bass  you thing will spawn? This is a closed lake, but there is one area where the lake in kind a narrowing down, to abut 50 feet across, and to get to that area from  the open water, I have to go trough a  large size of hydra field. This hydra field sometime a good place to fish, but never caught bugger than 4 pound there.
The coldest water temperature is this time of the year. I got a lots of luck to catch small and small/mid size bass up to 4-6 pound.
But there has to be a lot bigger that that. This lake is natural lake, and since this subdivision is around , 1987,, there is only catch and release. it has to be big boys in the lake.And there is only a few people fishing, mostly residents.
This time of the year , my best experience it , to use worms, all kinds of color.
Weird, but the top water baits is almost never works, even  in the warmest sunny mornings or evenings.
Also I trying to use different baits ,like crank baits, buzz bait,spoons , spinners as well.
I trying to locate the bait fish , hoping that will lead me to the big boys, but it is very hard . Not so many  activity on the top of the water . 
Once again, I can catch  small size bass all day long,  especially in the mornings, but the big ones just not came yet.
If you guys could please give me any advise, about anything, I would really appreciate that.
I am fishing since I was 6, now I am 42. I know (i thinK) what to look for, but obviously I missing out something.
If you guys need any more information , let me know. there is a lot more , I just thought this is the most important .
That you guys for help.

Thank you,
 

[SHaugh]

My advice would be to invest in a fish locator so you can better understand the lake.  You should be trying to spot the underwater structure that could be holding larger fish.

[quanjig]

170ft in south Florida?? Is it a pit lake of some kind?? 

[Turkey sandwich]

170 feet is crazy deep for Florida.  You're going to want to get sonar (you can get a lot for under $300) and actually check out the lake for structure.  

 

[GLADES]

Where is this lake exactly? Coral Cay?

[Zsolt Rebek-Nagy]

Coral Bay subdivision. West of 441. The size  of the lake is about 150 Acres , not 500. Sorry guys, that was a mistyping

Thanks  for the info, yeah I need to do some invest into sonars.

I will keep update .

Thanks

[atcoha]

I lived on a similar lake in miami a long time ago. The drop off was about 25-30 yards out, it dropped off to about 20-30'.

With no boat, we would either swim or paddle a surfboard with a bream or bluegill hooked to our line and drop it in a little past the dropoff.

Worked for us.