Guild Wars 2

I am new to GW2 so I have to ask stupid questions. Sorry about that. When playing WvW the leader often stops the zerg and tells us to put down speed. Then we charge into the fray. Many people comment on their 2 min or more speed duration, while I , at best, get maybe 30 sec. Playing necro does not give me a lot of speed options. Is there a blast finisher I should be using to get longer speed boost? If so what do I do when the static fields are down?

Thanks for your assistance.

Bump … Its a really great server