I think it would be best to go with Garmin because Professor Blahnik has already researched the Garmin protocol and knows how to read coordinates off of it. I also think we should get a unit with WAAS because it provides higher accuracy than those without. Here is a comparison chart of all Garmin WAAS models:
| eTrex Legend | eTrex Venture | eTrex Vista | GPS 76 | |
| Receiver | 12 channel | 12 channel | 12 channel | 12 channel |
| Number of Waypoints | 500 | 500 | 500 | 500 |
| Built in Memory | 8 MB | 1 MB | 24 MB | 1 MB |
| # of Routes / # of waypoints per route | 20/50 | 20/50 | 20/50 | 50/50 |
| Database or Basemap | Basemap (details) | Worldwide city database | Basemap (details) | Navaid and city database |
| Additional map options | MapSource CD-ROM uploadable information | MapSource Points of Interest CD (September 2001) | MapSource CD-ROM uploadable information | MapSource Points of Interest CD (September 2001) |
| Battery Life | 18 HR (2 AA) | 20 HR (2 AA) | 12 HR (2 AA) | 16 HR (2 AA) |
| Display Size | 2.1 x 1.1 | 2.1 x 1.1 | 2.1 x 1.1 | 2.2 x 1.6 |
| Display type | 4 level Gray LCD | 4 level Gray LCD | 4 level Gray LCD | 4 level Gray LCD |
| Pixels (H x W) | 288 x 160 | 288 x 160 | 288 x 160 | 240 x 180 |
| Standard GPS Antenna | Built in | Built in | Built in | Built in quad helix |
| TracBack Mode | Yes | Yes | Yes | Yes |
| # of Tracklog Points | 2048 | 2048 | 3000 | 2048 |
| Unit Weight | 5.3 oz. | 5.3 oz. | 5.3 oz. | 1 lb. |
| Audible Alarms | No | No | No | Anchor: Yes Arrival: Yes Clock: No Off Course: Yes |
| Waterproof Standard | IPX7 | IPX7 | IPX7 | IPX7 |
| Unit Size (H x W x D) | 4.4 x 2.0 x 1.2 | 4.4 x 2.0 x 1.2 | 4.4 x 2.0 x 1.2 | 6.2 x 2.7 x 1.4 |
| Click Stick (5 position cursor switch) | Yes | Yes | Yes | This Feature is not applicable to this Product |
| Backlit Display | Single level | Single level | Single level | Single level |
| Ext. Ant. Hookup | N/A | N/A | N/A | Yes |
| Internal Differential | This Feature is not applicable to this Product | This Feature is not applicable to this Product | This Feature is not applicable to this Product | N/A |
| WAAS capability | Yes | Yes | Yes | Yes |
| Loran TD position format | Yes | Yes | Yes | Yes |
| MGRS position format | Yes | Yes | Yes | Yes |
| Built-In Electronic Compass | This Feature is not applicable to this Product | This Feature is not applicable to this Product | Yes | This Feature is not applicable to this Product |
| Built-In Barometric Altimeter | This Feature is not applicable to this Product | This Feature is not applicable to this Product | Yes | This Feature is not applicable to this Product |
| Hunting/Fishing calculator | Yes | Yes | Yes | Yes |
| Celestial Information Page | Yes | Yes | Yes | Yes |
| Proximity Waypoints | N/A | N/A | N/A | Yes |
| Tide Prediction | This Feature is not applicable to this Product | This Feature is not applicable to this Product | This Feature is not applicable to this Product | Yes |
| Built in calendar | Yes | Yes | Yes | This Feature is not applicable to this Product |
| Voltage Range | 2.5 | 2.5 | 2.5 | 10-40 |
| Waypoint Icons | Yes | Yes | Yes | Yes |
| MSRP | $268 | $194 | $375 | $251 |
| WalMart.com | $248 | $168 | $348 | $218 |
| Power/Data Cord | $50 | $50 | $50 | $45 |
All of these come with a data cable. If we would like to power the GPS unit from the 12V power source, we will need a cable that doubles as the power cord and the data cord. However, we would not need to purchase this type of cable for $45 or $50 if we ran the GPS unit off of AA batteries. Given the predicted battery life of 12-20 hours on 2 AA batteries, this might be OK, especially initially.
After looking at the four models presented above, I would recommend the GPS 76. It is the only model to offer the quad-helix internal antenna (better reception/accuracy) and an external antenna jack that could be used in the future. It is somewhat larger and heavier than the other models, but I think we can sacrifice some mobility for better accuracy given the application, especially since it will be connected to a somewhat heavy laptop all of the time.