Originally Posted by kerlstone
could you recomend a gps, im not really up with all this tech stuff,
I assume we are are talking handheld here. If so then here are some questions to think about
1. Do you just want to know your position or do you want it on a map. If you are happy using charts on the boat you may be fine with a very basic unit. People will tell you you should carry charts anyway. I do and have basic charts on my hand held GPS. I could be persuaded that a very large scale chart (or do I mean small scale? - one covering a large geographic area on a small bit of paper) would be fine for most stuff I would do as usually I can see the shore anyway.
2. If you want it on a map, then you are going to be relatively close to the shore so probably the "base map" won't be enough to be useful. So then you need "charts". Charts come in different formats, details, costs. Beware some of the cheapest will assume you aren't going to go far inshore (e.g. much north of Port Appin on Loch Linnhe has very little detail (buoys/depths etc on my Lowrance cheap one). If you are planning to use much inland you might also want to check out the loch details - e.g. Loch Lomond is shown on some but not on others.
3. If you want charts do you need colour? My previous hand held had colour charts. This was nice, but not essential. On such a small screen colour helps a tiny bit (to convey extra info) but its not really possible to do any passage planning on a 2" screen anyway, it will tell you where you are and which way you should be pointing.
4. Do you want to plan routes on the PC and upload them. Make sure you can with the cables / cards provided and your PC. Beware some upload cables can cost almost 50% of the equipment price on budget models.
5. Do you want to use it for anything else (e.g. hill walking, mountainbiking, the bizare practice of geocaching etc). That might add size constraints that you won't have with a standard boat model.
6. Power - how long will it last? what size batteries does it take (might be helpful if they are the same as your VHF if it has an "alkaline battery tray")? I'm guessing you have no electrics on board, if you do - can you charge/run from them?
Whatever you decide make sure it is properly waterproof. Floating would be good, but a suitable lanyard should avoid 99% of disasters.
Like the VHF probably best to stick to common makes, like Garmin, Lowrance, etc. If you do go down the Lowrance route beware the manuals are terrible and the user interface is not particularly intuitive. If you can play with it before you buy as user interface will make the difference between you getting a lot out of it, and it sitting in a pocket until you are lost, then trying to remember how to turn it on!
There was a rumour that S/Horizon would be launching their VHF/GPS combined hand held in the UK in the next month - that might be worth checking out if (1) you just want positions (2) it has properly integrated the DSC functions (3) you don't mind all your eggs in one basket [imagine it stops working / falls overboard - if it were just the GPS, even if you are lost the VHF will gie the CG a reasonable idea of your location, and help to find you; if its just the VHF at least you still know where you are and can head for safety]. I think there are a couple of others Uniden? who are offering combined units with the DSC integration disabled in the UK (because of a licensing / approval issue) if storage/space etc is an issue might be worth considering.
Another possibility is an iPhone with the charting software on it. If there is a good waterproof container, and you don't mind risking a very expensive phone this is very impressive. I'm not sure I would use this as my only option; but if I had an iPhone anyway I might go for a very cheap, very basic unit and use the iPhone as my "plotter".
and does my yamaha 15hp 2st have a shear pin, id carry a spare if it does,
no, I think you'll have a rubber hub that "slips" if you hit something rather than a pin that breaks. If you are going as far as Rum then you might want to consider a spare prop, and prop spanner in your kit (the RNLI cleverly bolt their spare prop to the outside of the transom if storage is an issue) - because if you smash the prop landing on the beach on Rum - you might have an issue if it knocks it completely out of balance.