I've a level 5 frigate and I've no problem getting to the helm. Perhaps it was fixed?
I did buy a lvl 1 galleon before and couldn't get to the helm to save me bum.
Usually what I do is pull up near a ship and fire my broadsides. Then I jump down to my cannons and fire at the masts for a bit till I get notifiied that my broadsides can be used again and run back to the helm and fire. Rinse and repeat.
It's alot of back and forth, but I get some really nice exp for both my cannons and sailing. Plus I'm not waiting around for the "cool down" of my broadsides.
Stay outa jail!
-SH