The idea of a fixed number of calories per hour (ie energy used) from complex sports is a myth. The amount of energy used / time reflects the intensity of that activity. In order words the amount of and intensity of the muscular and cardiovascular strain.
A slightly better way would be to break it down like this in categories of low / medium and high intensity bands. For example see this nice infographic.
However a more precise way is to measure intensity more accurately. This has been perfected in cycling....because power (effort / energy use) increases with speed / resistance gradient
Similarly in rowing for example on the concept 2 rower
A new start up has also created the worlds first powermeter for running (more on this another time) see http://www.dcrainmaker.com/2015/01/stryd-first-running.html
Conclusion. Effort in a number of sports varies enormously. You can go for a gentle swim cycle jog or a really intense one. A really intense effort probably has a lot of hidden benefits in terms of HIIT after effect. More on that another time.