Automatic sounder boat (with DST800 nmea-2000)

Hello,

I'm new in this forum (sorry for my english. This is not my first language)

I have the project to create an automatic sounder boat.
For that I have to:
-Create an application to put the course of the boat on a map. (finished)
-Recover the GPS position of the boat. (finished)
-Acquire data from a compass and calculate the new direction of the boat. (finished)
-Display on a map the depths of the body of water (simulate in a .txt file) (finished)
-Show this card on a local ethernet server. (finished)
-Take information from the dst800 sensor (nmea 2000 standard). (I can't do it)

I have a DST800 sensor (depth sensor, speed and temperature).
This sensor works with the NMEA2000 standard.
I am using a seeed CAN shield (v1-2) (CAN-BUS Shield V1.2 | Seeed Studio Wiki)
And i use an arduino MEGA 2560 and a 12V continuous stable power supply.
I think i need to use the "ttlappalainen" library (ttlappalainen (Timo Lappalainen) ยท GitHub).

Someone would have managed to acquire the data from this sensor?
If yes, how did you do it?

thank you in advance