People have problems feeding dogs. Dolphin food is even more expensive. And few people have bathtubs big enough.

There are people that have spent decades working with dolphins. They have been used for some of the things you suggest and other things too, but they are very challenging and expensive to work with. This is clearly a job for professionals.

I think <taming> should be the right word. Let them be ashore and call them to duty whenever required by using sonar waves.

Dolphins are large, powerful and potentially dangerous wild animals. Training them is no more appropriate for an average person than training lions, tigers or bears.

Correction. In that last post it should read "taming" where it says "training".

Taming animals is challanging anyway even horses, dogs, cats, monkeys or any other for that sake.

The first batch would most challanging I suppose but not the subsequent ones, they will learn a great deal only by watching and imitating the other tamed.

The point here is to accept this challange and make use of the their potential.

I agree that taming Dolphins is not possible for any ordinary individual,If you have a look at the list of kind of jobs they are supposed to perform, most of them easily qualify for initiation and finacing from govt, life saving organizations and concerned institutions.

One more common climatic phenomenon in the near future would be flooding, both by rivers and seas and no technology can out-perform Dolphins in life saving operations under flood conditions.

If desired, private people can hire them whenever needed.

As long as we're entertaining immense impracticalities we might as well tame whales who are also supposed to be quite intelligent. A fleet of whales towing goods might initiate a relationships that could result in more intellectual exchanges to improve the rather limited intelligence humanity has demonstrated here and in other more dangerous venues.