To DSI or not DSI

So, I'm shopping for a fish finder/GPS combo as my birthday/father's day gift from my wife and kids (I'm past the point of caring about getting a surprise for such gifts - and as I'm the only paycheck earner, it's my money buying it anyway).

Anyway, I was looking at the Lowrance Mark 4.  I was going to stick with the regular, non-DSI version due mostly to the lower cost.  But Cabelas has a sale on them right now so I could justify the small increase in costs for the "upgrade" to the DSI version.

My concern though is twofold.  One - will the reduced depth capabilities of the DSI version be a handicap?  Most of the time I would think not.  The DSI is supposedly good for 200-250ft.  Very few lakes are deeper than that, and much of the Sound as depth restrictions around 120ft for bottom fish.  Even for salmon I doubt very much that I'd be needing sounder capability past 200ft.  But maybe I'm wrong on that.

My other big concern was whether DSI would overly complicate/data saturate the whole fishing experience.  Especially since I've never used a fish-finder of any type before.

Thoughts?

I'd suggest sticking with the regular one. I have this unit installed and haven't had the best results thus far. Perhaps it's my install skills but there seems to be noticeably difference between the detail in 10-30 feet of water and say 40-100. It has cool detail on the bottom in those lower depths but it doesn't seem to return good fish arcs very often. I end up staring at little lines and wondering, is that a fish? I like the idiot version of my old eagle where it showed me a little fishy. I had it installed on my Classic and wasn't happy with the results, but I'm not sure the transducer was staying flat. The DSI has a small rounded transducer and I think it might have been rotating with my first install. I've only used it on my Revo once and got similar results to what I got on the classic, not very good. I believe Sinker said he moved his DSI from just forward of the mirage drive (where mine is now)  to under his seat and that seemed to help. If I had to do it again I would just get the regular model.

Also, I learned that the degree of "waterproof" on a fishfinder does not include submersion. While out on loan, a certain someone flipped my classic and submerged the FF, which completely fried it. It also got small amounts of water on the inside when it was splashed a few times by waves out in the salt. Lowrance did replace it under warranty, so i will try and keep it dry this time I may install a second foam puck under the seat and see if I can notice a difference. Find me at ORC if you want to take it for a spin and check out the FF.

That would be great to try it out.

Noah, you should take a look at Marie's when we're at ORC and see if the detail is better/worse than what you're getting.

Noah, you should take a look at Marie's when we're at ORC and see if the detail is better/worse than what you're getting.

Will do. Does she get good fish arcs?

dunno yet.  We've either been bottom fishing or trolling in less than 20' of water since I put it in.

My experience pretty much my Mark 4 mirrors Noah's, although I mounted mine externally and have pretty good signals. I'm just not sure the detail really helps a lot. The round transducer shape made me think i was better off going with a external mount, as I don't know how far to the side the signals radiate. I also don't have any prior experience with FF's to compare DSI against . There are no Fish ID arches with DSI, although I have seen fish.

The one way it is exactly the same is that it fried after my huli at PC; it was not powered on at the time, but when I powered it on it  flickered 3 times and died. Water got in the SD slot and drained out slowly for two days - the cover is not designed to handle turbulence, although it is rated IPx7. I returned it to Lowrance under warranty and am awaiting a replacement. I am going to tape the slot closed on the next one, and remove it when I'm in any surf zone.

Will do. Does she get good fish arcs?

I have a regular-mode, color Humminbird FF and rarely see good fish arcs.  To create a good arc a fish has to pass evenly through the center of the sonar sound cone.  This occurs when the fish is suspended, stationary over the bottom, or barely moving.  This is rare.  Fish move around a lot, particularly in the salt.  If the fish is swimming against your direction of travel it is not in the sonar cone long enough and may look like a blob.  If the fish is swimming with your direction of travel it will create a meandering line.  I see this fairly often when bottom fishing and the fish are following my jig - long lines descending and ascending.  If the fish is ascending or descending you will see a straight to angled line.  In many cases the FISH ID function does not recognize these meandering lines and blobs as fish. 

The only prefect solution would be some sort of submerged starlight camera system.

My 597 HD DI is like having a glass bottom boat. I see fish and if the jig is under the kayak, I see it also.

My 597 HD DI is like having a glass bottom boat. I see fish and if the jig is under the kayak, I see it also.

How is the transducer mounted on your setup?

My 597 HD DI is like having a glass bottom boat. I see fish and if the jig is under the kayak, I see it also.

How is the transducer mounted on your setup?

shoot through, mounted under the sonar shield, foam and water

My 597 HD DI is like having a glass bottom boat. I see fish and if the jig is under the kayak, I see it also.

How deep does that performance persist?

My 597 HD DI is like having a glass bottom boat. I see fish and if the jig is under the kayak, I see it also.

How deep does that performance persist?

I haven't done a lot of deep fishing with it yet. The signature of the lead jig head probably fades after 100 feet.

I also like the DI in how it returns images of the fish's "air bladder." I think it lets you judge the size of what's down there more accurately than viewing arcs.

This morning I installed a second puck just under the seat of the Revo. Over the next three days I will try and see if I notice any difference between the two. I'll try and remember to take a picture of two.

This morning I installed a second puck just under the seat of the Revo. Over the next three days I will try and see if I notice any difference between the two. I'll try and remember to take a picture of two.

It may also be interesting if you can also hang/hold the transducer directly in the water and take a screen shot.