My brother and I did three last night, the two x-long deck drains and one in the front storage comparment (we did the other two last week). We used the tool that Fr. Frank mentioned (see link below). Make sure you put the brass washers in the approprate sequence on the tool...if not, it can be quite a fight. Same goes for cutting to length...cut too long...makes for a lot of work.
Lastly, it's possible to make them too tight...don't ask.
Here's a link to the tool...
http://www.marinepowerservice.com/bo...roductID=11405