The papers in this issue arise from those presented at the 15th biennial Joint Numerical Sea Modelling Group (JONSMOD) conference that was held in the beautiful old city of Delft in the Netherlands, from 10th to 12th May 2010.

The JONSMOD community is a group of about 100 researchers interested in modelling shallow sea dynamics. More details about the history of JONSMOD can be found in the 2007 issue of Ocean Dynamics (volume 57, issues 4 and 5). About 95 scientists participated in the Delft meeting, mostly from (11) European countries, while several researchers joined from overseas: USA, Canada, New Zealand and Singapore. A record number of 70(!) scientific papers were presented. Perhaps a pointer for the future, 20% of the participants was female. The interest in the meeting and subsequent large number of presentations made us decide to organise two parallel sessions during the second of the 3 days, which was a novelty for JONSMOD.

The venue of the meeting was Deltares (formerly Delft Hydraulics). It was already the third time that JONSMOD conferences have been hosted by Deltares-Delft Hydraulics, and the organisation was again excellent.

The present volume contains 20 of the best papers that were presented during the Delft conference. This time, both of us were appointed as Associate Editors of Ocean Dynamics, and we were able to use the excellent offices of the Journal which streamlined the considerable administration that is traditionally involved. This is responsible in a large measure for the timely publication of this volume.

All of the papers have been through the standard refereeing procedure of Ocean Dynamics, and we thank all the authors for their hard work and all the referees for their considerable help. We know that there are still spam filters that treat pleas to act as a referee as spam, and this caused one or two delays, but we forget how different things were only 8 years ago when snail mail was still used. This slight inconvenience is a small price to pay.

The 16th JONSMOD meeting is scheduled for 2012 and will be held in Brittany in northwest France with local organisation coordinated by Pierre Garreau of IFREMER. Anyone who wants more information should either visit the JONSMOD website at www.jonsmod.org or contact the authors.

May 2011

Herman Gerritsen (Deltares-Delft Hydraulics, Delft)

Phil P.G. Dyke (University of Plymouth, Plymouth, UK)