The greatest difference between fishing vessels and other vessels is that the fishing vessels are working when at sea.

A cargo vessels loads and unloads in harbour and at sea merely gets from A to B as quickly and safely as possible. The fishing vessel has to catch, process and stow its catch at sea while taking into its stride the best efforts of wind and waves.

The design of fishing vessels and in particular trawlers is thus a compromise of many factors. The vessel needs to be powerful to tow a trawl yet closewinded so as to regain the windgage after a long downwind tow, fast enough to get the catch back to port in good condition, have sufficient initial stability to stand up to the wind yet be easy enough to be comfortable to work aboard and avoid excessive strain on the rig and gear – and  be built strong enough to work in most weathers and to survive in all weathers. Smacks had a working life of many decades: a concept in wooden boats which is difficult to accept nowadays.

Over the years the design of the smacks changed but slowly. They were built larger for deep sea trawling, faster when to be used primarily as carriers but the change in design was not pronounced. Thus vessels which were purpose built as well smacks could be used for fleeting until such time as they could be transferred to lining full-time or sold to another fishery, and presumably owners were reluctant to change as long as the vessels were still earning them money.

At the end of the 18th and beginning of the 19th centuries fishing vessels were usually deep, beamy, clench built craft probably around 30ft long. They were rigged with a single mast, and the mainsail was large and the boom long so as to provide good drive. The mainsail was loose footed as this set produces more power on the reach and downwind, ie when towing a trawl. In the 1820’s Samuel Hewett had two lists of Barking smacks, the new smacks under sixty years old and the old smacks over sixty years old! It is also said that in his latter days he felt that the smacks that were then being built were of inferior quality and would not last more than 15 or 20 years – times don’t change!

As the smacks began to work further offshore, they had to cope with heavier weather as they could not get home so quickly. This distance from home also meant that they had to catch their fish more quickly so as to allow for travelling time when heading back to market. Thus they were built larger, especially when they had to incorporate a well. Carvel became the preferred method of construction. With the fleeting system, and the use of ice, however, the well was no longer really necessary when trawling with the fleet and dry smacks were built. These could carry the fish and ice and were faster because they were not full of seawater. There was, however, a need to remain flexible and with the well ships being also well suited to the lining fisheries it must be assumed that there was a long period of time when well smacks fished alongside dry smacks purpose built for fleeting.

With the use of purpose built carriers to carry the fish to market, the trawlers could place more emphasis on power than speed, which led in time to the use of the ketch. Many existing vessels were lengthened by 10 or 15, sometimes 20ft and a mizzen mast stepped forward of the tiller. Between 1865 and 1875 some 100 smacks were slipped and lengthened this way at Gorleston. By leaving the mainmast in its original setting this mast was now relatively further forward on the lengthened vessel and could provide a stable yet powerful drive force. To make sail handling easier and thus minimise the number of crew required they shortened the main boom, and there were five or six different headsails.. These vessels wee also more deeply ballasted, carrying from 70 to 100 tons of which a good proportion was kentledge (pig-iron). The extra length also allowed a longer beam to be used.

Technology also produced the steam capstan, which was fitted to the smacks as from about 1880. These added to both the initial and the running costs but it made hauling much easier and quicker, and reduced the number of crew required. There were many accidents in the early years – not least caused by the crew using salt water in the boiler. Several vessels ended up with a pillar of salt in the cabin.

Towards the end of the 19th century the fleeters were all very similar in design, dandy rigged and about 80 to 90ft long, but technological progress meant that some began to be built of iron. Initially some composite craft were built (such as Brunette 1865) with wooden planking on iron frames, but all iron vessels soon followed. These were not popular with the fisherman, not only because they felt then as they do today that wooden boats are more seakindly, but also because they were suspicious of the use of heavy iron which sinks. Several did sink, which didn’t help their confidence. By the end of the century, though, a large proportion of the vessels were iron.