Sorry... no experience of Glasgow Nautical College.
But please don't let your distance from any Distance Learning school influence your choice. As you say, it is only for four weeks, and Bristol (and, I assume, all the other DL schools) will send you list of extremely cheap but very good accomodation in the area. Travel is very often not expensive if booked in advance, either.
With the price of each exam about to be (or has it already been?) increased, anything you'd save by going to a less suitable school that's closer to home could be wiped out even by having to do just one resit.
FFF
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