He is also the co-developer,[1] along with Professor H. Ronald Riggs of the University of Hawaiʻi, of the computer program HYDRAN for solving linear fluid-structure interaction problems of floating and fixed bodies.

Following the encouragement of his advisor, Prof. M Cengiz Dokmeci, he moved to the Department of Naval Architecture and Offshore Engineering of the University of California, Berkeley, United States, for higher education.

In the era of PCs, for example, Professor Ertekin played a key role in transferring the department from one focusing mostly on field and experimental studies, to also a leading institute in modern and computational hydrodynamics.

The department was the host of some of the internationally leading conferences, workshops and meetings (details given below), mostly organized and chaired by Cengiz.

Other topics of significant research contribution by Ertekin include ship resistance, marine energy, and oil spills.

Although the GN equations were developed very recently (compared to other wave theories), they are well-known and fairly understood by the research and scientific community.

Working under close guidance of his advisors, he was one of the first to use the nonlinear equations (that were introduced just a couple of years earlier by Profs.

In his Ph.D. dissertation, Ertekin was the first to give the equations in now a familiar form to the hydrodynamics community by providing closed-form relations for the pressures.

Due to the unprecedented long length, displacement and associated hydroelastic response of VLFS, the state of the art analysis and design approaches that was used for smaller floating platforms was not adequate.

It quickly became obvious that new approaches must be developed to tackle the complex problems associated to dynamics and response of VLFS.

Ertekin has also introduced new approaches and equations to study this topic, including the use of nonlinear water wave models to analyse the hydroelastic response of VLFS of mat type (see e.g.,[32][33][34] and [35]).

His work and research on hydroelasticity of VLFS has opened a new era for these topics and gave more confidence in understanding the dynamics and response of the structures.

[36][37][38][39] They developed models used to assess the vulnerability of coastal bridges in USA to tsunami and storm surge and waves.