## 1 Introduction
### Literature Review  
Concerning the use of Deeper Smart Sonar in science, [PERSON] et al. [7] used the Deeper Smart Sonar Pro+ connected to a UAV via a winch to survey three inland water bodies in Denmark: Lake Fureso, Marrebaek Kanal and Amose A. The authors estimated that the Global Navigation Satellite System (GNSS) receiver built into the Deeper Smart Sonar Pro+ had an accuracy of several metres (up to 30) and, through comparison with sample depth measurements, that the sonar committed an error of 3.8%. [PERSON] et al. [7] then proposed a method of correcting the horizontal positioning of the SBES using the nadiral images acquired by a UAV equipped with GNSS, Inertial Measurement Unit (IMU) and RAdio Detection And Ranging (RADAR) sensors, while the depth was corrected by linear regression with ground truths collected during the survey. After applying these methods, the authors obtained a horizontal positioning accuracy of about 20 cm and an error of about 2.1% for depths up to about 30 metres. [PERSON] et al. [8], through the integration of UAV imagery, sonar (data from the Deeper Smart Sonar Pro+) and adaptive sampling, surveyed a small reservoir located at the Kessler Atmospheric and Ecological Field Station (KAEFS) near Purcell, Oklahoma, USA. In order to perform the survey, the authors connected the SBES to a UAV via a cable and a small vessel containing an Android tablet to collect bathymetric data. [PERSON] et al. (2018), comparing the direct measurements with echosounder measurements, observed a Root Mean Square Error (RMSE) of 0.0147 and an R of 0.987. [PERSON] et al. [9] used the Deeper Smart Sonar Pro+, connected to a bait boat, to collect depth measurements of small-to-medium water bodies (between 50,000 and 2000 square metres) located in Tuscany. The authors described the sonar's internal GNSS as \"highly accurate\". From the acquired data, the authors deduced the volume of the water bodies investigated (204) and found a high correlation (R\({}^{2}\) = 94) between the deduced volumes and the actual volumes of some sampled water bodies (55). [PERSON] et al. [10] by combining data from UAVs, georadar and two sonars, one of them a Deeper Smart Sonar Pro+, surveyed the Seyakha C11 crater in Siberia and produced a Digital Elevation Model (DEM) of it. The Deeper Smart Sonar Pro+ was geolocated with the internal GNSS and the authors reported a positioning accuracy of up to 3 metres. [PERSON] et al. [11] used the Deeper Smart Sonar CHIRP+ (technological successor of the Pro+) with other sensors to study the recession processes of the Pasterze glacier in Austria. Using the CHIRP+, the authors highlighted that there was a lack of reference studies on the CHIRP+ that indicated the accuracy of SBES in measuring depth. However, the authors estimated the accuracy of water depth measurements of less than 0.1 m in shallow waters (<5 m) and flat bottoms, and 0.5 m for deeper waters with sloping bottoms. [PERSON] et al. [12] used the Deeper Smart Sonar CHIRP+ to detect suspended macro-plastics in rivers. The authors demonstrated with this research that they could detect suspended macro-plastics with low-cost sonar and that specific plastic objects had different reflections. [PERSON] et al. [13] tested a system called \"Dronar\" for forensic purposes. The system consisted of a Deeper Smart Sonar (Pro+ or CHIRP+ 2) connected by wire to a UAV. The authors showed how the Dronar could be a system to identify sunken objects, provide background information for further investigation and signal possible dangers to the navigation of boats and divers. [PERSON] et al. [14] developed a floating UAV system for measuring natural river discharge. The system consisted of a UAV equipped with a floating ring, a Global Positioning System-Real-Time Kinematic (GPS-RTK) receiver (DG-PRO1 RWS) a smartphone for data recording and a Deeper Smart Sonar Pro+. By combining the GPS-RTK receiver to measure the river's velocity and the sonar to take cross-sections, the authors were able to derive the discharge of the river. [PERSON] et al.