I couldn't say about a 140 but I have a 210 b+w, it seems to work ok up to about 150 ft. I have used it in both fresh and salt water, performance is about the same, only good for trolling speed, any faster and it loses signal,batterys last a long time. I used it every day for 2 weeks last summer on the same batterys.
Thanks for the response dan t.. I have an old Humminbird portable with a suction cup transducer similar to your unit, but over 20 years old, and I was fairly pleased with it till it quit working. It still powers on but it doesn't do anything else. I think the transducer is shot, but I can't get a new replacement, obsolete. The 140 I'm considering is a clamp on unit with the transducer permanently mounted on a pole that is attached to the display unit, and if it preforms ok it'd be real handy for me.
