With weekend temperatures expected to climb to 30 degrees on Saturday and 26 on Sunday, in combination with school holidays and a long weekend, the number of people enjoying beaches and waterways is set to surge.

But beach swimmers will need to take full responsibility for their own safety, because life guards will not be on duty at Victorian beaches.

The first warm weekend in months is also a timely reminder that incidents on the water can end in fatalities. In the 2014-15 financial year, there were 39 drowning deaths across Victoria.

Since July last year, seven people have died while fishing from a recreational craft in Victorian waters, water police figures show.

Senior sergeant Alistair Nisbet, head of the water police squad, said boat users should conduct a thorough check of their vessel well in advance of heading out on the water.

He also urged boating enthusiasts to ensure all their safety gear was on board and in working order, to carry a fully charged mobile phone on board, a torch with fresh batteries and to tell family members who remained on shore where they were launching their boat and where they planned to fish or visit.

And with extra swimmers, kayakers and jet ski users also in the water, senior sergeant Nisbet advised people to consider other safety messages too.

If water users were concerned by the behaviour of jet ski users they should call 000. And he urged kayakers to be aware of their level of fitness, and the fact they were sitting in a kayak rather than a sizeable boat when enjoying places like Port Phillip Bay.

Kayaks are becoming an increasingly popular vessel for fishing, but Mr Nisbet said some users needed to be better prepared.

"Kayakers represent a significant number of the fatalities that we investigate. It's almost a quarter of our fatalities over the last four or five years," he said.

"What we find is that people don't understand the seriousness of going out in some of these waters. And they can end up in a position where they might not understand their own fitness ability, they might not understand or they're not looking at the weather conditions and the effect of that weather on the waterway.

"They face the potential of going into the water, (but) they're not practising, or they're not honing their skills on their craft and being able to get back onto that craft in deep water. They may be under-prepared in their dress," he said.

Greg Scott from Life Saving Victoria urged people to take responsibility for themselves, consider their ability before heading to the beach, never swim alone, to look after children near water and stay out of the water if they have been drinking alcohol.

"It's the first bout of warm weather in quite some months and people probably aren't especially thinking water safety, but more about the opportunity they have to cool off and enjoy the water, especially given a long weekend and the hot weather.

"It will be a potentially risky time because when you couple the hot weather with the long weekend, and the potential for people to have been consuming alcohol, along with the fact that there isn't any patrols on the beach – it could be a bit of a worry," he said.