Rod design is one of those subjects that I think I know more about than anyone else. There are a surprising number of these subjects when it comes down to it, and luckily for the rest of the universe, I usually keep my opinion to myself (unless asked for it, of course).
Firstly let me state that the action of a rod is a separate quality to that of it's recovery speed, and although the two can be related they are can also be different... this is emphasised when you include rods manufactured from materials other than carbon; such as cane, glass or tank aerials. Different carbon compositions have a similar effect.
This is not widely understood and this has been highlighted in the last answer.
A tip action rod means just that; a rod that will only flex at the tip, no matter how much force is applied. There are such rods around. I do not like them. A progressive action is far more versatile. You can choose where to bend this rod when you make the cast and by simply altering the casting arc to match for the bend in the rod, you can cast a narrow loop. This is in fact one of the most basic fundamentals behind good flycasting technique.
Most quality rods are progressive, even though the marketing may state otherwise. Not all rods are, however, and some are purely tip flexing. These rods can only ever be cast in a narrow arc. In order to increase line speed the caster ends up having to cast making use of an elbow extension; ie "push".
Progressive actions, especially those rods that flex almost to the handle, are best cast by pulling the rod.
The speed of the rod is the speed of the tip recovery. If you were to anchor the butt section and pull the rod tip down and then release it, the resulting vibration could be measured. The higher the frequency; the faster the blank. Most importantly, fast blanks feel crisp in the hand. I like a fast progressive action.
I find that they cast further than tip actions since I can "wind them up".
I have written an article on this subject called "sexyrod". As well as this, and for a further understanding, I would suggest you read casting strokes, maximum power, rod angles, casting points and Arden flycasting. As you can see this subject has had fairly extensive coverage on this site :-)
To answer the original question (and I am allowed to do this since it wasn't my question); most saltwater rods are progressive and not tip action, it is simply a case of confusion over terminology. However I should also add that most flycasters are pushers of the rod and not pullers :-)
Moving swiftly on...
I have some other questions that have been niggling me slightly, such as my leader. The minimum length I recommend for trout fishing is one and a half times the length of the rod. In saltwater everyone seems to use a nine-foot leader. I realise that this is because we do not use such fine tippets and besides the saltwater flies are bigger, more wind-resistant and require more energy to turn them over. I always use a tapered leader, these being cheap, long lasting, giving the smoothest transfer of energy and without knots. Many saltwater flyfishers I have read (I haven't met many) construct very complicated leaders using special knots and secret formulae. What do you guys do? :-)
Following on from the very successful introduction of the soon-to-be patented Arden-grass drag system do you think that it is important to spend a large amount of money on a saltwater flyreel? I have heard stories of reels melting down. And what of anti-reverse... is this an unnecessary embellishment?
And lastly, let us say that I don't actually manage to catch anything out of Dunedin Harbour, and that Sunshine Beach merely gives me sunshine, then where in the world (literally please) would you suggest I try next? Gary you don't have to answer this since you have already done so, although you may want to change location given the following criteria: I'm looking for somewhere with large fish (or at least fish) that are easily seen, it's got to be warm, sunny, fishable from the shore (for starters), cheap and above all else, a place where there are lots of beautiful women (Cathy: is Barry allowed to answer this?) :-)... and is there such a place?