Both those options would work well. There are other AIS transceivers with WiFi built in that would give you the same basic performance as option 2. Those include products from ACR and Em-Trak. Any of the AIS transceivers with WiFi built in may or may not translate all the data available from either NMEA 0183 or NMEA 2000 and make it available to a mobile device. 

Options like the Yacht Devices NMEA 2000 Router or similar converters and WiFi products from Digital Yacht and Actisense can potentially convert the output of older, disparate electronics and give you a single stream of data with AIS, depth, wind, location and other information all bundled together. 

-Ben S.

Also, if your friend's boat cruises at over 14 knots of if they are often in AIS congested waters, they should probably get the newer form of Class B AIS called SOTDMA or B/SO or B+. Explanation here:

https://panbo.com/class-b-ais-so-cs-transmit-rates-truth-vs-confusion/

The Si-Tex MDA-5 is a good example of a Class B/SO with WiFi and antenna splitter built in, but there are many choices.

And I highly recommend Milltech Marine as a great source of AIS information as that's all they sell and they carry many brands:

https://www.milltechmarine.com/

Entry level AIS receiver from Quark is also a good choice. QK-A026 works well on my tablet with Navionics 

Have similar question: already have an older SITEX AIS Transceiver (class B) and an antenna splitter. It can only connect via USB to external devices (e.g. a laptop). I'd like to add a WIFI Gateway such that tables/ipads can also get the data stream (and add it to the Navionics app).  Anyone have configuration proposals? I've seen a few gateways but not clear how they would connect....

Chris, does the Si-Tex AIS have a NMEA 2000 port? If so, I think that the Actisense W2K-1 is an excellent WiFi gateway:

https://actisense.com/products/w2k-1-nmea-2000-wifi-gateway/

If the output is only NMEA 0183 -- besides for the USB -- you might consider the Yacht Device YDWR:

https://yachtdevicesus.com/products/nmea-0183-wifi-router-ydwr-02

It's a year after my last post here and I think the em-track B953 has become the leading contender - low power, SOTDMA and a built-in antenna splitter, plus they're physically pretty small. Nice to see advances in this area.