If you ssh into a computer and want to use tcpdump to view traffic, ssh (22) can be excluded

tcpdump -I [interface] -n 'port!22'

Capture traffic leaving a host

tcpdump -pi [interface] src host [hostname]

Watch for traffic leaving one network and entering two other networks

tcpdump -pi [interface] src net [network] and dst net [network2] or [network3]
tcpdump -pi [interface] src net 128.128.252.0/28 and dst 192.168.11.0/24 or 192.168.12/24

To see what computers are up, what OS they are running and what ports are open:

nmap -sS -O [network]    ie: nmap -sS -O 192.168.11.0

To look at https traffic on the science network:

iftop -i [interface] -f "dst port 443" 

Need to setup a server (sender) and client (listener)

On shore just listen
       iperf -s -u
On shore listen on a certain port    
    iperf -s -u -p 55437

From ship, send 7 M
   iperf -c [shoreip number]  -u -t 120 -b 7M