A curious anchor from Sir Bu Na’air Island, UAE

Introduction

In December 2021, a team of Portuguese archaeologists and historians conducted an underwater survey at Sir Bu Na’air, in the United Arab Emirates. This survey was part of a cooperation program between the Sharjah Archaeology Authority, located in the United Arab Emirates (UAE), and the Instituto de Arqueologia e Paleociências / Historia, Territorios e Comunidades from NOVA University of Lisbon and the University of Coimbra, in Portugal.

The Sharjah Emirate has a strong focus on cultural heritage and has implemented a number of policies and initiatives to preserve and promote its cultural resources. The results of the 2021 survey were published (Carita et al. 2022), but there was an interesting find that deserves more attention: a modern anchor that looks like a replica of a stone anchor.

Stone anchors have been used since before the Bronze Age and are still an effective solution to anchor small craft (refs here). It is possible that there are more anchors of this typology in the Persian Gulf, but this is the only one we have seen so far, and its typology invites the present study. A review of the bibliography did not yield any parallels, and that is the main reason why we are publishing this paper.

The most important component of this paper is the computer graphics treatment that allowed us to publish this interesting artifact in detail, and share it with the scholarly community.

The Island

The island of Sir Bu Na’air is located in the south of the Arabian Gulf, north and northwest from the United Arab Emirates mainland. With a total area of 13.2 square kilometres, the island maximum length reaches about 5.9 km between its farthest points, with a width of 3.9 km in an east-west direction.

Although Sir Bu Na’air appears in cartography since at least the 18th century, the oldest known written mentions to Sir Bu Na’air date to the 19^th century and can be found in The Persian Gulf Pilot, probably the most authoritative information on the Gulf islands still today. Too small to harbour a large permanent settlement, The Persian Gulf Pilot says that in the winter fishermen from Sharjah and Dubai camped there with their families, near some wells of brackish water. Salt mines were explored there in the late 19^th century, and in 1935 a British company was granted the “right to recover and export any specular (Shining) Iron Ore.” Some workers had their families on the island.

In 2000, the ruler of Sharjah, His Highness Sheikh Sultan bin Mohammed Al-Qasimi, declared the island a protected area for its value as a cultural heritage site and a growing concern with the conservation of natural areas and preservation of animal and plant species, both on land and sea.

The Anchor

The anchor was found during a survey dive, in an anchorage, on the southeast side of the island, together with other artifacts and a stone anchor.

It is a singular artifact, assembled from a solid round stainless steel plate, with a welded suspension ring and two hooks, miming the function of stone anchors from Votruba’s classification PSF3SA, staked with two wooden pieces (Figure 1).

Figure 1. Gregory Votruba’s classification of stone anchors  (Votruba 2019).

This anchor is not perfectly circular. It has a width of 43.5 cm, and a height of 47.9 cm. The suspension ring diameter is 15 cm, and its thickness is 3.5 cm (Figure 2). We could not find any parallel example to this anchor and decided to publish it in the hope that more examples may be found.

Figure 2. The Sir Bu Na’air anchor (Filipe Castro) and the model (Frederico Henriques).

Digital Model

When the survey was interrupted by bad weather, we hang the anchor from a peer and took a series of pictures with a telephone, while rotating it around its vertical axis.

Back at the  Research Center in Arts Sciences and Technologies (CITAR), from the Portuguese Catholic University (UCP), Frederico Henriques cleaned the pictures’ background and developed a photogrammetric model from which he made a 3D model, filled the blind spots, textured the surface, and created a rigorous model that can be published and shared with scholars around the world.

Computer graphics have revolutionized archaeology. Representations of archaeological contexts and objects were complex and 2D representations were sometimes insufficient. Software that creates 3D representations simplified the publishing process and allowed previously impossible story telling strategies, including animations and immersive technologies (https://www.youtube.com/watch?v=XYLjqFfWOAk). 

Figure 3. The Sir Bu Na’air anchor model (Frederico Henriques).

Conclusions

Archaeology is the study of past human activity based on material remains of that past. This anchor is modern, but it is a reiteration of a typology that has proven itself effective for thousands of years. It stands as an example of the social value of archaeology, reminding us how the past is around us, and how it determines who we are in complex ways.