Welcome to the Marine Electronics Forums presented by Panbo and SeaBits.
Hotspot connection with WIFI router
I did a quick search and did not find any related topics.
I have installed a wifi/router (Netgear C7000v2) on our boat. When in the marina it is connected to the outside coax cable to provide internet access to all wifi devices on board. Is there a way to connect a IPhone as a hotspot to the wifi/router when under way (disconnected) to provide the internet access? There are a lot of devices connected to the wifi and I don't like to re-map all of them when using an hotspot. I read some articles about bridge'ing the wifi/router but could not figure out.
You have a couple of choices. One, and likely the cheapest, would be to replace the Netgear C7000 with a router capable of multiple connection types. I've just reviewed a $69 option that would do exactly what you want. It's the GL.iNet AR750s and it manages connections via Ethernet, WiFi and USB sources.
Alternatively, you could get a WiFi bridge that will convert the WiFi from your phone to Ethernet. This will actually prove to be more expensive and require switching the cable between the marina internet connection and the wireless bridge. Marine specific wireless bridges are available from companies like Digital Yacht, Wave WiFi, RedPort Global and others.
Thanks Ben for the answer that review sounds really good just read through it.
Also I was listening to the podcast, very informative.
Only concern I have is that the GL.iNet is currently not available and if I need to get my cable service re-configured (with XFinity / Comcast). I remember that they needed to register the router on their side for activation.
 I just saw that the unit does not has a coax port, so I might still need to use the Netgear and connect to the GL.iNet?
Do you know if there is a similar product like the GL.iNet on the market?
I didn't realize you were terminating your cable connection directly to the Netgear. That means your current Netgear router is doing double duty as both a cable modem and router. I don't believe you will find any travel routers with cable modems built in since travel routers are designed for use on the go where you wouldn't typically have a cable internet connection. Your use case does come with both. So, I think you have two options, one, as you mentioned, use the Netgear to land the cable internet connection and then connect it to a port on the GL.iNet device or two, get a dedicated cable modem without a router and connect that to the GL.iNet router.
If you go with option 1, you might want to figure out how to put the Netgear into passthrough mode so you're not doing something called double NAT'ing. It's not a huge problem but can introduce some complexities.
@ben-stein Thanks that really worked. Got my cable connected as well as the Iphone. Only thing is that the range is limited (less than the netgear router), do you have any recommendation to install a 12V WIFI extender so I can get a signal everywhere on the boat?
@pilotmarcus I'm not too surprised to hear you have less range. The travel router is a physically small product with short little antennas and an overall lower power design. You likely have two options, one is to use a typical range extender that receives WiFi from the travel router and rebroadcasts it ( https://amzn.to/3hIX8V3 - this one uses a 12v transformer so you can just clip the transformer off the wires and go directly to a 12v power source) or you could use a full wireless access point ( https://amzn.to/2QDOhrR) again with a 12v input that can be fed directly from the boat's 12v system.
I've found that trying to make full use of combined features in various devices... is often a fool's errand. Both at home and on the boat. You can't get this to work, or that, or both, and then there's coverage woes or no space available to make the antennas fit. Using separate devices often gets better results.
As more devices on board have wifi you're going to run into trouble if you don't have reliable connectivity from them to the boat's wifi network.
I've put a Ubiquiti nano access point on my boat. I power it from 12v using a 12v to 48v Power over Ethernet injector (from Tycon). I have the nano wired into a 12vdc gigabit Ethernet switch. To which, for the moment, I have wired to a gl-inet 750S travel router. The travel router's local wifi coverage was weak, at best. But does a semi-decent job of picking up the marina's WiFi. So I disabled the local WiFi network on the router, and let the Ubiquiti handle it. I have cell data connecting via a USB modem.
This separation also lets me reboot the router without any of the other on-board wifi devices getting confused.
Ethernet switch: https://www.amazon.com/gp/product/B073Z73TGX
The Unifi devices have a controller that can be used to set them up. You can get their own device called a Cloud Key or you can install the controller software on anything else that runs Java. I have a Raspberry Pi 4 that handles this (and some other networking functions). To help smooth power for the pi4 I have a pi sugar UPS battery keeping it going. I've got a 12v-USB buck converter powering the setup.
There are other kinds of battery backup units for the pi, but the pi sugar units have some decent integration software, and they're relatively inexpensive. What I don't yet have is a case suitable to contain the pi4 and battery backup. They're working on a 3D printable case.
Ideally I'd like to find a metal case, as I'm wary of how Lithium batteries may age over time. If a battery fails I'd prefer the resulting problem didn't set surrounding materials ablaze.
I do not see the travel router as my ideal solution. It's ok, but it's throughput is weak. As has been pointed out, marina wifi is often too congested to be useful. But it's nice to have the option to keep the boat connected while we're gone, and not have it burn through a ton of cell data.
One very nice thing about the gl-inet router is their Android app. It's easy to use and allows doing all the router setup and network changes without a web browser. As in, we motor somewhere, and then I use my phone to check the router's cellular or wifi coverage and select them as necessary. Too few of the other devices out there have a decent, easy to use way to do this. Sure, you CAN do it with a web browser, logging into this, that and the other... but a combined app sure makes it a lot less hassle.
Using a better device like a peplink or something would be more reliable and provide better WAN cellular performance. The trick would be arranging the failover between wifi and cell data in useful ways. Just because you have a strong shore wifi signal doesn't mean you want to use it. Failover isn't always an easy thing to configure.
Anyway, my point is if you're expecting to find just ONE device to handle EVERYTHING... be prepared for disappointment.