Our new instrument display is pictured here. That's probably the best thing we did for the boat in St. Martin, replacing our instru- ments. The old Datamarine instruments worked for 25 years, so we feel they gave good service. The depth sounder went out in Luperon, almost a year ago, and we've been using a Humminbird transom mount unit, lowered on an old boat hook into the water and hose- clamped to the monitor. It worked very well and now we know we have a good backup unit for the depth. Speed and distance would work sometimes, but not often.
We chose a Navman unit, which so far we've been pleased with. Our requirements are simple - we don't have a chart plotter, radar, or console GPS, so we didn't need to interface with other instruments and displays. We have been living without speed and distance now for a while, but now that we have it we really like to see. Our unit displays a log (like a trip meter), a total log distance, speed, average speed, battery voltage (!), depth, and .... it slices, dices and makes our life easier !
Our instrument display unit, with two thru-hull transducers, was about $440 at Island Water World. The comparable unit at Budget Marine was Raymarine, and just over $700. So we feel like we got a good deal and are having fun learning all the features of the display.