This is a good unit. I have a hds 5- gen 2 and hds7- gen 3 on my boat. They both will link together but the gen 3 will preform Side imaging and down imaging if you buy the extra transducer. I would recommend on seeing the difference in price between the Gen 2 and Gen 3. If there isn't much cost difference I would go with the Gen 3 if you ever consider using SI or DI.