No there are not new technologies forcompact antennas. The more compact the antenna the lower the gain. The antenna will have a coil at the base or distributed along the antenna to create the correct electrical impedance. A 6db antenna is typically 5/8wave length.
Now, having said that, the location of an antenna is also a major factor. There are two fctors to consider here.
VHF communication is line of site. This means that the higher an antenna (within reason) the better the performance. Often getting the antenna higher will perform better than increased gain.
The second factor that is harder to visualize is the pattern. An antenna installed on a boat or vehicle will be affected by what is beneath it and what is around it. For example, if it is against a metal cabin, the performance in the direction of the metal will be poor. A metal pole, for example mounting on the side of a radar arch will cause poor performanc in that direction. So the best location will be clear of any intrfering objects.
Finally an answer to your question, an antenna with a stainless whip and a coil at the base mounted at the top of your cabin will probably work as effectively as a fibreglass antenna mounted on the gunwhale. If the stainless whip antenna was mounted on the gunwhale it would not work as well as the longer antenna. If you happen to have a radar arch or can mount the antenna on top of the cabin, a stainless whip with base coil will work well. If you are operating in a location where you have good range, that combination will work well also. It will suffer in this location if you are marginal to the station that you want to communicate with already.
I could probably ramble on more, but can address any specific questions you may have.