Until 1968, the only method of position fixing for surveys in the estuary was by means of shore transits and horizontal sextant angles. In 1968, to make possible the large scale surveying requirements of the newly created Sunk Dredged Channel, a Decca Hi-fix chain was established to cover the area from sea to Immingham. At the same time a survey office was opened at Grimsby to carry out monitoring work in the S.D.C., the Humber entrance and the Humber approaches. This situation remained until 1985, when the automation of position fixing was extended to cover the greater part of the survey area by the establishment of a Racal Micro-fix system. The first survey using this system was carried out on 4th. July 1985.
The final elements necessary to fully automate the survey system were the measurement and recording of depths and tidal levels digitally. To this end, trials were held with a digitised echo-sounder in October, 1987, but these were unsuccessful and it was decided to retain the analogue Atlas Deso 20 echo sounders, interfaced with TSS 335 heave compensators to provide a digital output. This was then combined with an on-line, post-processing and tide handling software package supplied by Norcom Technology Ltd.
At the same time, a chart construction and production system was developed in-house, initially employing the sections' geographical information system (G.I.S.), transferring, by 1996, to AutoCAD as the design and drafting software package.
During the latter part of 1991, it was decided to extend the tidal monitoring system, which had been initially established in 1985 by Sonar Research and Development Ltd. (SRD), which provided information from sonar tide gauges at six sites by means of a mixture of radio and land line links.
The existing sonar gauges were retained and a further nine units were installed during 1992, these being linked both to the survey offices and to Vessel Traffic Services (VTS) Humber by means of a scanning telemetry system, located on the Humber Bridge, developed by Magenta Systems Ltd., this enabled the full streamlining of chart production.
Also during 1991, two new 15 metre Halmatic fast survey launches, "Humber Charter" and "Humber Ranger" were commissioned. The increase in launch speed allowing a vessel working from Hull to be deployed in the Upper Humber survey area, which inevitably lead to the closing down of the long-established Brough Survey Office, its staff transferring to the Hull office.
In 1994, in order to further improve the accuracy of position fixing, extensive trials were undertaken with the newly-developed D.G.P.S. (Differential Global Positioning System) equipment offered by several manufacturers, culminating, in 1995, in the purchase and fitting to survey vessels and the buoy vessel, of Sercel equipment supplied by Ormston Technology Ltd. This allowed the removal of the fifteen permanent Micro-fix shore stations and their replacement by just three reference stations at Spurn, Hull and Blacktoft to provide differential corrections to the raw G.P.S. received on the vessels, enabling dynamic position accuracies of around one metre anywhere in the estuary or docks.
A replacement at Grimsby for the ageing survey launch "Humber Surveyor" was sought in 1995, to provide a stable surveying platform for work in the Humber entrance and approaches. This requirement was met by the purchase of the 20 metre catamaran "Spirit of Fife" which was converted during 1996 from an ex channel islands passenger ferry to a survey vessel, which eventually inherited the " Humber Surveyor" name.
At the end of 1997, as a prelude to a major re-organisation of the harbour masters department, the survey office based at Grimsby was closed and its team disbanded, the "Humber Surveyor" and remaining manager moving to Hull.
The effect of the reorganisation on the survey section was that pilot launch coxswains and crewmen replaced the permanent crews of the three survey craft on an "as needed" basis. In addition, these men were instructed in the gathering of hydrographic field data, for later processing by hydrographic surveyors in the office.
During the early part of 1998, the "Humber Surveyor" was fitted out with a multibeam echo sounder, owned and operated by Sonar Research and Development Ltd., which allowed the vessel to undertake a number of trial swath surveys in the River Ouse, downstream of Goole. These successfully showed that the swath system gave a far more comprehensive picture of the river bed, compared with the existing "track" surveying system.
Following this, a "joint venture" system was set up between ABP and SRD, The "Humber Surveyor" being then utilised by them on a number of occasions to carry out pipeline and wreck inspection surveys as far afield as the west coast of the UK, Peterhead and the Thames Estuary, as well as the near continent.