Navman 3100 series
I installed Navman 3100 depth, speed, and wind instruments in my 1989 Hunter 30G this summer (with some help from my yard, which handled the masthead wind transducer). My previous boat had a comparable ST60 setup. Both systems perform admirably. Indeed, they are quite similar. Both have proprietary bus architectures (for connecting the instruments to each other and to a GPS/chartplotter) but also work with the NMEA standard. The Raymarine instruments offer many more features, most of which I never used; on balance, I'd say that the Navman instruments are more ergonomic -- easier and less confusing to use. Either system is a good bet; Navman got the edge, for me, due to price (but that was before Raymarine offered package discounts). If you already have (or are planning to buy) a Raymarine autopilot & chartplotter, you'll find it somewhat easier to get everything working smoothly if you go for the Raymarine instruments (which "speak" the proprietary Raymarine SeaTalk communications protocol). I'm using the Navman 3100 instruments with a Standard Horizon CP160 plotter and a Raymarine ST4000+ autopilot, and I'm quite pleased with the results.