In most cases, the need to see forward occurs when traveling from deeper to shallower depths. Forward scanning is possible but limited when the water is less than 10' deep. Some clutter on the screen will occur in shallow environments. The maximum forward range in a vertical scan, is six times forward the depth. In a horizontal scan, the maximum forward is four times the depth.
All units are available with either a transom or thru-hull transducer configuration.
If you are operating an inboard, you must use the thru-hull. Remember that you are measuring ahead from the transducer , therefore, placing it as far forward as possible will provide you with greater forward range. The transom transducers are mounted on a stainless steel kick-up bracket to minimize the possibility of damage if striking a floating object. The transom bracket will 'kick-up' at speeds in excess of about 25 knots. Therefore, if you intend on using the forward scan at high speed, you will need to consider a thru-hull transducer .