VHF Antenna lengths

[seafari25]

My fathers old 21' Calais tunnel hull, which he purchased second hand, came with 2 VHF antennas. The one installed on the boat was a 4' steel which we replaced with an 8' whip which was laying in the cabin. i'm not sure what each db were however I do know that the 4 footer had a much greater range. We changed it because the 8 footer looked better but later realized that the original owner may have changed it due to the better range as he used the boat mostly for off shore purposes.

Also I seem to remember that antennas should be matched with the radio. I'm not sure if that is just for CB's and just with the older models or if this is even a factor today.