## 1 Introduction  
Icebergs and ice islands (large, tabular icebergs) calved from high-latitude glaciers and ice shelves pose a threat to vessels and offshore infrastructure at a time when Arctic shipping and resource exploration is increasing [1]. In the Canadian Arctic, ship traffic has increased by more than 75% over the past decade, and the continued reduction of sea ice is anticipated to further increase accessibility to the maritime Arctic [2]. Knowledge of the location of potential ice hazards is critical for ensuring safe and efficient operations [3]; however, observations from satellites, aerial reconnaissance, and shipping are often obtained on an intermittent basis and over limited areas. There is a growing demand for tracking data of representative, potentially hazardous, or unique icebergs for risk management and applied and fundamental research [4]. However, there is a lack of reliable in situ field observations of iceberg drift from these regions due in large part to the high cost of commercial tracking devices [5]. Tracking beacons have been used to measure the movements of ice in the Arctic over the past several decades [5, 6, 7, 8, 9, 10, 11, 12, 13]. Beacons could be used to complement radar and aircraft reconnaissance, providing a valuable source of information for mitigating and managing risk to industrial operations and infrastructure in ice-infested waters [14]. Data on the short-term motion of icebergs can be used to develop and enhance drift and deterioration models [15, 16], while longer-term trajectories can be used to improve iceberg detection algorithms in satellite imagery [17] as well as modelling [18, 19]. A better understanding of the long-term movement of ice can be used to derive drift climatologies [20], explore the influence of iceberg melt on ocean properties [21], or provide context in case studies [20; 22]. In addition to positional information, ancillary data from tracking beacons, including heading and tilt, can also help determine how icebergs are drifting and deteriorating. Current technologies used for tracking ice drift rely on Global Navigation Satellite Systems (GNSS) for positioning information, which typically provides positional accuracy of up to a few meters [23]. However, accuracy can be influenced by different sources of measurement error, such as satellite orbits, effects of the atmosphere, and receiver and antenna selection [24]. Telemetry of data is most often achieved using the Iridium satellite network [12; 13; 25], which offers excellent coverage over the polar regions and bi-directional data transmission in near real time. Other satellite communication platforms include ARGOS [9; 26; 27] and Globalstar [28; 29], but these lack positional precision or do not offer coverage at high latitudes. Some recent studies [29; 30] have started to explore the use of low-cost technologies to study the drift of icebergs. The application of such technologies has the potential to greatly reduce the cost of monitoring the drift of icebergs, as reliance on expensive and proprietary commercial tracking devices presents a significant barrier to the establishment of widespread monitoring networks. For these reasons, there is a need for cost-effective instrumentation that is easily adaptable and sufficiently robust for long-term remote usage. Thus, the development of an inexpensive, user-friendly ice drift tracking beacon represents a significant advancement for the collection of in situ iceberg observations from previously data-sparse regions. Here, we describe the design and construction of the Cryologger Ice Tracking Beacon (ITB), a low-cost, rugged tracking beacon that can be assembled at a cost that is 5-10 times less than existing commercial alternatives. We detail the initial prototype (v1.0) and a subsequent design revision (v2.0) that have been deployed on icebergs and ice islands in the Canadian Arctic. We use these 16 deployments to demonstrate the features of the ITB and highlight lessons learned as we tested these designs.