I use their earlier "economy crimper", which has grooves to hold the crimp and attached punches which you hit with a hammer to make an indent in the crimp.
Last time I needed it, it was ashore, and so I just used a suitable punch. Providing the crimp is a tight fit on the cable, I think this is all you need.
I bought some re-useable cable lugs from ebay. They work by having two bolts which you tighten up to hold the cable in place. Much stronger than trdaitional cable lugs and more expensive - but how many do you need!
Only problem is that they are bulky if you are very tight for space.
why crimp ? the best connection is a soldered connection just use a blowlamp and put the stripped cable into the terminal, a little flux , and fill with solder ! best type of conductor you,ll ever have .
Thanks for all the advice - would have used a vice if I had a strong enough one on the boat so used the mole grips as suggested - will beef it up with some solder.