interlinking and gps on a humminbird

if i have a 998 interlinked with the same gps with the 858 and i mark a brush pile with the 998 will my marked spot show up on the 858?

Yes it will with the InterLink. If you have both units setup to fully participate in the network; than marking a waypoint will save the waypoint to the unit you marked it on, it will save it to the InterLink and save it in the second unit as well.

With those two units though you could Ethernet connect them. Saving a waypoint on one unit will make it available for use on the second unit – but without taking up any memory space on the second unit. There are also other sharing possibilities with the Ethernet that the InterLink cannot be made to do.

so i could interlink or ethernet them and still get the same results to my question, which is the cheaper route?

go the Ethernet route, better overall & as Greg says it saves on only one unit but will share it to the 2nd unit(therefor you are not using up 2 way point memories for one way point) and yes is a little cheaper. Ethernet system much more reliable..

I would agree with everything that jaxsprat stated except for the “little cheaper” part. Depending on which Ethernet cable(s) you have to get – it could be a lot cheaper! Example: for your two units (998 and 858) all you need is one Ethernet Connection cable. If you need a 20 foot cable it will run you about $60 versus about $130 for an InterLink.
AS EC 20E

AS INTERLINK :: Humminbird