Under this heading one has calls for bunkering which can, on occasion, be lengthy. For estimating purposes, however, it is sufficient to allocate one day for each call. Canal transit inevitably lengthens the voyage and it is safer to allow 2 days each for passage through Suez and Panama because time can be lost waiting, as well as during the transit itself. It is not normal to allow additional steaming time for possible bad weather, unless it is certain from the nature of the voyage that delay will be experienced. Once the main essentials are available the calculations can begin; these broadly consist of income minus expenditure. The form and procedure used is a matter of personal opinion but they can all be classified under one heading – method. Most companies will have their own layout depending, to some extent, on the type of ship they work but the example below is as good as any. It is very easy to reduce an estimate to ‘the back of an envelope’ and, indeed, there are times when speed of negotiating will make this imperative. Before that stage is reached, considerable experience will have to be gained at a more leisurely pace and this is where a set format is so essential. If all the various items of income and expenditure are set out it is far more difficult to forget the odd item, which can make the difference between profit and loss. So, if one is likely to be involved in regular voyage estimating , d raft out a suitable form and use it constantly. There are, of course, computer programmes for voyage estimating but mastering the manual method is vital in order to avoid stupid mistakes with the computer. The estimate can, of course, be made quite adequately on plain paper; the vital thing is to acquire method. In this Lesson the following method is suggested and the later examples are based on this system: Plan out the voyage, duration and bunker consumption. This will enable you to see at a glance just what is intended. Call this the itinerary. Next calculate what cargo can be loaded. Sometimes this section needs to be completed in conjunction with the itinerary – for example when port time is assessed against a daily loading or discharging rate. Tabulate all expenses. Bunkers; Port and Canal costs; stevedoring; despatch; extra insurance premium are prominent examples. Assess Income and Profit and Loss.