Thanks for the reply Tim, the thing we are most concerned with is doing the trip as safely as possible... especially due to this stretch of the Thames having large high speed craft sharing the water with us... we are mostly worried about the wash from these larger vessels along with the strong current of the Thames and how it might affect our small narrowboat.
We have an anchor on board, I will have to check the requirements for the chain length and make sure ours matches up. We also have life jackets however we do not have a VHF, nor are either of us licensed to use one...
I appreciate your reply and will send you a pm for more info, Thanks!